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157 Cards in this Set

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Hypothesis

a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

A hypothesis is sometimes described as an educated guess.

Prediction

Forecasting the results of a action or test.

Law

A scientific law is a statement based on repeated experimental observations that describes some aspects of the universe. A scientific law always applies under the same conditions...

"Okay Jim, we get it. This is the eighteenth time you've dropped the bass. Gravity's a thing."

Theory

a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.

an idea or set of ideas that is intended to explain facts or events

Scientific Method

a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.

The scientific method is defined as a method of research in which a problem is identified, relevant data is gathered, a hypothesis is formulated from this data, and the hypothesis is empirically tested.

Crypsis

crypsis is the ability of an organism to avoid observation or detection by other organisms.

Encryption - protecting data with something else (kinda)

Aposematism

Antisemitism is one form of an "advertising" signal (with many others existing, such as the bright colors of flowers which lure pollinators).

It's like those geckos and their bright dulaps, using bright colors as signals.


"Apose..." Like striking a pose!

Mimicry

the action or art of imitating someone or something, typically in order to entertain or ridicule. Or in this case, make yourself look more fierce than you actually are.

Endemic vs Native

endemic means occurring nowhere else, restricted or peculiar to a locality or region;


native implies birth or origin in a particular place:

Native = Born here

Endemic = Not from here

Evolution

Evolution is a process that results in changes in the genetic material of a population over time.

Natural Selection

the process whereby organisms better adapted to their environment tend to survive and produce more offspring

Only the strong survive.

Sexual Selection

natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.

Only the ones that are most attractive survive.

Convergent Evolution

Convergent evolution is the independent evolution of similar features in species of different lineages.

Converge, means to come together.

Species

a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding

If they breed together, then they're a species.

Monophyly

monophyleticgroup is a taxon (group of organisms) which forms a clade, meaning that it consists of an ancestral species and all its descendants

ancestral species and all its descendants


(mono = 1)

Polyphyly

Polyphyly is a term in cladistics. It describes a group of organisms whose last common ancestor is not a member of the group.

this is an ancestral taxon and all its descendants PLUS additional species that don't belong there

(Poly = many)

Paraphyly

Paraphyly is a term in cladistics. It means a group which does not include all its descendents.

Paraphrasing, an ancestral species and SOME of it's descended.

Herp Evolution (basic outline)

d
d

Nuclear DNA

Nuclear DNA, or nuclear deoxyribonucleic acid (nDNA), is DNAcontained within a nucleus of eukaryotic organisms. Nuclear DNAencodes for the majority of the genome in eukaryotes, with DNA located in mitochondria and plastids coding for the rest.

Like the yellow part of the egg, it contains the majority of information.

Mitochondrial DNA

Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNAcan be found in the cell nucleus and, in plants, in the chloroplast.

Like the white-stuff surrounding the egg, contains a small portion of information.

Gene

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

A gene is what's transferred from parent to child, like the red-headed gene.

Allele

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Alternate form of a gene that can change over time.

Mutation

the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

A change of a gene that can be passed down the generations.

List them in order: Family,genus, Species, Order

OFGS

Ectothermy

is an organism in which internal physiological sources of heat are of relatively small or quite negligible importance in controlling body temperature. Some refer to these organisms as "cold blooded". Such organisms (for example frogs) rely on environmental heat sources, which permits them to operate at very economical metabolic rates.

Cold Blooded; Uses the environment for heat generation.

Endothermy

physiological generation and regulation of body temperature by metabolic means : the property or state of being warm-blooded. In other words, you get your heat internally rather than from the environment.

Warm Blooded; Doesn't use the environment for heat generation.

Indeterminate Growth

Once achieving sexual maturity, growth can continue.

Determinate Growth

Once achieving sexual maturity, growing stops.

What colors do Melanophores pigments control?

Brown / Black / Red

Melano - BBR

What colors do Iridophores pigments control?

Several colors; mostly Blue

Iridophores - Indigo - Blue

What colors do Xanthophores pigments control?

Yellow / Orange/ Red

Xanth - YOR -

Linnaean Taxonomy

It's a rigidly ordered hierarchy, 'OFGS' May/may not accurately represent relatedness between species

It's rough around the edges. Just like Communism.

Paedomorphic

It relates to Aquatic; 'If a salamander is paedomorphic, you would expect it to be:'

Paedo = Child morphic = water...?

The Biological Species Concept

The biological species concept defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance.

If it breeds together, then it's a species.

Phylogenetic Species Concept

Classifying organisms by shared descent

Disregarding wither or not if they breed together, it's all about their ancestors.


'Phylo - Parent'

Monophyly

In common cladistic usage, a monophyletic group is a taxon (group of organisms) which forms a clade, meaning that it consists of an ancestral species and all its descendants

Ancestral species and all of it's descendants.

Polyphyly

Polyphyly is a term in cladistics. It describes a group of organisms whose last common ancestor is not a member of the group. Another way of expressing this is to say that polyphyly includes groups some members of which are descended from ancestral populations.

For example, if we were to lump squirrels into the group "reptilia." Think "poly" (many) for too many taxa in the grouping.

Paraphyly

It means a group which does not include all its descendents.

A great example is the old definition of reptiles, where birds were not included. We know now that birds are reptiles, but we used to think they were not closely related and so birds were excluded from reptilia (leaving reptilia paraphyletic)

Metamorphosis; Benefits

Can take advantage of aquatic and terrestrial habitats when suitable (especially predator‐free temporary pools), leave when unsuitable.

Anatomy & Physiology




Able to come and go into terrestrial habitats whenever it's best suitable.

Metamorphosis Drawbacks:

Need access to both habitats! Tied to water for breeding and larval development, land for adult stage

Anatomy & Physiology




Require both habitats, water for breeding and developing, and land for adulthood.

Metamorphosis Drawbacks; Solutions

– Stay in the water: paedomorphosis

– don’t metamorphose completely (Cope’s giant salamander, axolotl, etc.)


– Stay on land: direct development


– go through metamorphosis within the egg (most lungless salamanders [which is most of thespecies of salamanders!], many caecilians, some frogs).

Anatomy & Physiology




Choose a single habitat instead of going to land.


Don't metamorphose completely.


Or, metamorphosis in a safe environment

Anatomy & Physiology; Frogs vs Salamanders

Frog's metamorphosis is dramatic, Salamander metamorphosis is less so; Salamanders are carnivorous throughout life, frogs transition from herbi/detritivore to carnivore.

Anatomy & Physiology




Salamanders eat meat their entire lives. Frogs develop into it. Obv. Frog's metamorphosis is dramatic, unlike Salamanders.

Anatomy & Physiology; Growth Rates

Growth rate is influenced by availability of food:little food, little growth.

Anatomy & Physiology


Remember the Iguanas and the El Nino events and how they change size.

Anatomy & Physiology; Determinate Growth

– Growth slowsdramatically or stops atsexual maturity.

Anatomy & Physiology

Anatomy & Physiology; Indeterminate Growth

Sexually mature individuals continue to grow.

Anatomy & Physiology

Anatomy & Physiology ; Tail shedding

Squamates can disattach their tail to distract predators, can not detach again below a previous point.

Anatomy & Physiology

Anatomy & Physiology ; Regeneration

Regenerated tail is inferior to original, has cartilaginous instead of bones. This affects social and survival costs, as well as finding a mate.

Anatomy & Physiology




The new tail isn't like the old one, affecting everything.

Skin; Issues with Water Loss

Amphibian skin is thin and permeable, loses water freely to environment.

Anatomy & Physiology




Thin = more loss

Skin Glands

Amphibians have a Dermis, which contains poison and mucus glands. Mucus provides protection to skin, poison is a deterrent.

Anatomy & Physiology




Dermis produces mucus which can help contain the water.

skin; α (alpha)-keratin

α‐keratin is a structural protein found in other vertebrates. Flexible, elastic, somewhat tough (in humans, found in hair, skin, and fingernails). In reptiles, found in skin between the scales.

Anatomy & Physiology




Alpha keratin is found in nails, hair and skin in Humans. It's flexible.

skin; β (beta)-keratin

β‐keratin is unique to reptiles. Rigid, extremelytough and abrasion‐resistant. In reptiles, makes upthe scales.

Anatomy & Physiology




Beta is Best! It's tough!

Skins; Osteoderms

Bone armor, Crocs and Alligator lizerds have them.

Anatomy & Physiology

Skin; Color-changing chromatophores: Melanophores

bottom layer; imparts black, brown, red

Anatomy & Physiology




Melano - BBR

Skin; Color-changing chromatophores: Idirophores

middle layer; imparts several colors, particularly blue

Anatomy & Physiology




Idiro - Indigo

Skin; Color-changing chromatophores: Xanthophores

: top layer; imparts yellow, orange, red

Anatomy & Physiology




Xanth - YOR

Venom basics; why use venom

– Much safer and easier to ingest prey if it’s neutralized!

– Venom may start digestion with proteolytic enzymes.


– Can be used as a defense…

Anatomy & Physiology




Easier to digest as well as pre-digestion.

Respiratory system: Basics

• Cells need O2 to perform metabolic processes.

• There’s a lot of O2 in air; very little in water.


• There’s more O2 in water the colder it is andthe faster‐flowing flowing it is.

Anatomy & Physiology




Faster water = more air

Respiratory system: Breathing methods

Negative pressure breathing (creating anegative air pressure in lungs, which drawsin air).

– Positive pressure breathing (forcing air intothe lungs by increasing the air pressure).

Anatomy & Physiology




Negative - what we do


Positive - Gulping the air

Respiratory system: Importance of Surface area

More surface area = more oxygen into the creature.

Anatomy & Physiology




More is better

Respiratory system: Various respiratory surfaces; Lungs

Amphibian lung = wet sack.•Reptile lung = contains partitions, extrasurface area.

Anatomy & Physiology




Amphibians are wet!




Reptile lungs have partitions.

Respiratory system: Various respiratory surfaces; Gills

Only function underwater: collapse in the air.The larger and more branching, the more effectivethey are at extracting O2 from the water.

Anatomy & Physiology




They're like antennas, the longer they are the better the signal.

Respiratory system: Various respiratory surfaces; Skin (and extra skin)

Amphibian skin is extremely permeable, makes an excellent site for gas exchange (underwater and on land, as long as skin is wet). More skin = more surface area = more air passing.

Anatomy & Physiology




Also kinda like an atenna

Respiratory system: Various respiratory surfaces; Thin skin of the mouth and throat

Air flow across the thin skin in the buccopharyngeal cavity (mouth and throat). Occurs in lungless salamanders, fairly minor contribution to overall O2requirements.

Anatomy & Physiology




Thin skin in the cheek/throat area allows air to pass through.

Respiratory system: Various respiratory surfaces; Skin of the cloaca

Across the thin skin of the cloaca. Cloaca may have sacks with villi (cloacal bursae) to provide extra surface area

Anatomy & Physiology




This allows gas exchange while submerged, as well as more surface area

Respiratory system: Various respiratory surfaces; skin between scales

yellow‐bellied sea snakescan obtain ~1/3 of theirO2 demands through their skin.

Anatomy & Physiology




Not sure about this one, some snakes can get 1/3 of their O2 via their skins...?

Water Balance issues; methods of obtaining water

Amphibians gain most oftheir water through theirskin[And the pelvic patch, same function] (some through through thefood they eat). They donot drink orally.

Anatomy & Physiology




Amphibians drink through their skin and via their food.

Water Balance issues: water storage

Bladder can function as a water storage organ(amphibians can resorb water from bladder!). Australian water‐holding frog can store 130% ofnormal body mass in bladder water

Anatomy & Physiology




Water can fit in the bladder, Amphibians can reabsorb that stuff.

Water Balance issues; Minimizing water loss

Cocoons, skin waxing, stockpiling urea in blood

Anatomy & Physiology




Clog the holes! Even if it's your skin. Clog all the things!

Water Balance issues; Strategies of reptiles

Impermeable skin of reptiles = extremelyuseful. Allows for colonization of aridenvironments.


• Despite Despite impermeable impermeable skin, water is still acritical resource (especially in aridenvironments), and must be carefullymanaged.

Anatomy & Physiology




Reptiles certainly arn't as leaky as amphibians.


Though, water evaporates so it's scare.

Temperature regulation: Endothermy

The generation of body heat largely throughmetabolic processes

Anatomy & Physiology


Endo = In Doors

Temperature regulation: Ectothermy

The acquisition of body heat from the environment.

Anatomy & Physiology




Ecto = Out doors

Temperature regulation: Homeothermy

Maintenance ofa continuous body temperature.

Anatomy & Physiology


Homo = same

Temperature regulation: Heterothermy

Havinga variable body temperature

Anatomy & Physiology


Hetero = different; variable

Temperature regulation: Basking

Terrestrial Terrestrial amphibians amphibians tend to make little effort inthermoregulation: water loss issues make baskingproblematic.

Anatomy & Physiology





Anatomy & Physiology :Hibernation and aestivation

Hibernation is dormancy due to seasonal cold.

Aestivation is dormancy due to anything else(often drought).

Anatomy & Physiology


We all know what Hibernation is, bears do it during winter.


Aestvation is due to anything else BUT winter

Anatomy & Physiology: Freeze Tolerance

– Intracellular: destroys contents of cell. Lethal.


– Extracellular: Extracellular: as liquid water in bodybecomes solid, remaining solution becomesmore and more concentrated. Dehydratescells. Also blocks circulation.

Anatomy & Physiology


Intra - bad


Extra - good

What are senses for?

The senses relay the important aspects of the outside (and inside)world to facilitate facilitate survival survival and reproduction of the organism.

Sensory Biology


They take in information on the surroundings.

How do the senses work? Stimulus

Anything that happens

Sensory Biology




Stimulus is anything that happens.

How do the senses work? Detection

A stimulus triggers a sensory receptor. An organism canonly detect a stimulus if it has a sensory receptor sensitiveto the stimulus

Sensory Biology




Stimulus triggers the sensory receptors.

How do the senses work? Transduction

The sensory receptor sends an electrical impulse to thebrain telling the brain what it just detected.

Sensory Biology


Transduction is the sensory receptors sending an electrical message to the brain.

How do the senses work? Sensation

– The electric impulse that reaches the brain.

Sensory Biology




The transduction reaches the brain

How do the senses work? Perception

The brain’s awareness and interpretation of a sensation.

Sensory Biology




Perception is how the brain reacts to the transduction

Categories of senses

Photoreceptors: respond to photons of light


Thermoreceptors: respond to changes in temperature


Chemoreceptors: respond to the presence of chemicals.


Mechanoreceptors: respond to the physical distortion (e.g.stretching, compressing, twisting) of the receptor.


Magnetoreceptors: respond to the Earth’s magnetic field


Nociceptors (Pain): respond to stimuli usually resulting from tissuedamage

Sensory Biology


PTCMN


Photo


Thermo


Chemo


Mech/Mag


Nocic (Think, no pain)

Vision: visual pigments, cone and rod cells

Cones:– Low sensitivity to light.– High resolution.– Can be responsible for color vision, ifmore than one type is present.

Rods:– Highly sensitive to light.– Low resolution.– Good for low‐light detection and/ormotion detection.– Usually only one type of photopigment present in rods, and thus responsiblefor monochromatic vision.

Sensory Biology


Cones do color vision and have a low sensitivity to light


Rods are good for dark places due to low sensitivity. Contains only a single photopigment

Vision: Visual abilities of herps

Pupil shape: Elliptical (usually vertically oriented) is extremely effective atshutting out light when constricted shutting out light when constricted,useful in protecting especially sensitiveretina. Common among nocturnal taxa.

Sensory Biology


Pupil shape called Elliptical, it's vertical. Good for shutting out light.

Vision:Evolutionary history of vision in squamates

– Lizards lost their rods (presumably were specializedfor diurnal activity). But then some lizards evolvedto become nocturnal…

– Nocturnal lizard taxa have re‐evolved the ability tosee in low‐light conditions by modifying their cones.


– Snakes lost their cones, and almost their rods, too!(presumably were nocturnal/fossorial). But…


– Diurnal snakes have re‐evolved cones from theirrods

Sensory Biology


Lizards lost their rods, to evolve to nocturnal

Vision: Snake eyes

– Spherical lens (typical lensofa terrestrial terrestrial vertebrate vertebrate isflattened)

– Lens is moved back andforth to focus (typical lensofa terrestrial vertebratechanges shape to focus)


– Eyelids fused to formatransparent spectacle.

Sensory Biology


Snake's lenses can move back and forth to focus, like a camera

Vision: polarized light detection, 3rd eye, etc

As light passes through the atmosphere, some of itis scattered ina direction perpendicular to the sun.– Detection of this polarized light gives youa clue as towhere the sun is.

3rd Eye Located on top of the skull,connects with the pinealbody, transmitsinformation on ambient3rd eyeinformation on ambientlight (including polarizedlight, in some herps) topineal body.

Sensory Biology




Light hits atmosphere = gets rkt, the third eye picks up on that light to help locate the sun.

Infrared detection: Receptors

Infrared receptors are found on the headof some snakes. As well as labial pits on upper/lower lips. As well as loreal pits, pits between the nostril and eye. Provides stereoscopic vision.

Sensory Biology




Labial pits are located on the lips, with loreal pits more on the face. These are used to use IR as a way to navigate surroundings.

Infrared detection: Optimizing functionality,

Tradeoff with optimal IR detection functionality:

– Snakes need their body temperature to be warmenough to function


• This affects when and where IR‐detecting snakesare most active: – Temperate Zone: • Dusk: as environment cools and snake conserves body heat • Morning: after basking, but while environment is stillrelatively cool


– Tropics: • Night • Dusk and Dawn

Sensory Biology




Snakes need their internal temps to be right for it to be functional, which limits the time of day they can do it.

Chemoreception: Smell

Typically used forlong‐range detection(e.g., presenceoff d ooand its generallocation).

May initiate tounge-flicking repose in some taxa for close-range identification

Sensory Biology


Tongue flicking! Triangualte the target

Chemoreception: Vomerolfaction

Particularly sensitive to very high molecularweight compounds, which includes manypheromones:

– Intra‐ or interspecific: e.g., some fossorial snakes canraid ant nests by following ants’ chemical trail.


Snake's forked tounge try to triangulate the source o f the sent.

Sensory Biology




Able to detect molecular weight of certain compounds

Chemoreception: Taste

• Used during feeding asa final discriminatorregarding the palatability of what’s in the mouth.

• In squamates, taste buds are abundant in fleshy‐tongued taxa, and scarce in those with heavilykeratinized tongues.

Sensory Biology




Squamates with fleshy tounges have a lot of tastebuds, those with armored taste buds don't have that many.

Hearing

Amphibians:

– Most frogs possess tympana(= ear drums, tympanum is singular), andhave well‐developed hearing


Reptiles:


– Most lizards and crocodylians haveexternally visible ears (tympanamay or may not be recessed)– Snakes have no outer ear, but dohave an inner ear. Able to detectsubstrate‐borne and someairborne vibrations

Sensory Biology




Most frogs have a well-developed hearing, lizards and crocs have visible ears, but snakes don't have an outter ear, but have an inner ear.

Touch: Lateral line system

Mechanoreceptors in lateral linesystem consist of small sets of cilia(hair‐like cellular projections) thatonly bend in one direction.

Sensory Biology




The lateral line system is a touch-detection system, these small hairs bend in one direction

Magnetoreception

Ability to detect the magnetic field of the Earth.

Found in a wide range of herps.

Sensory Biology

Purpose of Communication

Males of a polygynous species; find mate, trade information about self and location.

Females of a polygynous species, locate and evaluate males

Communication




Why do we communication?

Roles of different sexes in communication

Males do most of the talking, females do most of the reciving

Communication

Components of Communication (signal, transmission medium, receiver, perception, and integration)

Signal: – Original strength of signal affects rate of reception • Transmission medium: – Interference of transmission medium may degrade signal,oftentimes rapidly

Receiving sensory structure (receptors of receivingindividual):


– Signal reception is limited by finite receiver sensitivity


Perception and integration of the signal: – What the receiving individual decides to do about the perceived signal, e.g., ignore, respond, etc.

Communication


Signal: i.e. the Wifi signal.


Transmission medium receiver: i.e. the wall inbetween the wifi and me.


Perception: What I do about the weak wifi signal.

Constraints and costs of communication

Signal broadcasting can be energeticallyexpensive • Broadcastinga signal of sufficient magnitudemay be difficult witha small body size • Environmental noise (signal interference)often high.

Communication


Broadcasing is expensive, it'll need to be loud enough so others can hear me, plus environmental noise. Also interception.

Methods of increasing signal reception

Make it bigger, louder.

If visual; brighter and vivid colors.


If auditory; make signal frequency different from background frequency


Visual signals in clearings, audio signals during quiet times. Change signal to best match the surroundings.

Communication




Change the signal or improve it to best match the surroundings.

Communication evolution

Communication is intimately tied to sensorymodes: evolution of communication is in lockstepwith evolution of sensory systems.

Communication


Communication evolves with sensory systems



Communication modes, their characteristics and how the different taxa make use of them


(The different modes of Communication)

Visual,


Acoustic,


Chemical,


Tactile,


Multimodal (2 of any of the above)

Communication


VACT,


Visual


Acoustic


Tactile



Communication: Visual Characteristics

Characteristics:– Moderate to close range– Typically most useful during the day– Easily obstructed, need line‐of‐sight for effectivetransmission– Location of source is easy

Communication


It's visual, think of it's range and usefulness.

Acoustic Communication:

• Characteristics: – Short to long range (often used in long range) – Day or night (often used at night) – Subject to noise interference from biotic or abioticsources– Location of source relatively straightforward, evenwith line‐of‐sight obstructions

Communication


Common among Frogs, Crocs and Geckos


Longer than visual, but suffers from other acoustic spam.

Chemical Communication:

Characteristics: – Short to long range – Day or night – Can be difficult to locate source – Cannot be readily modified, makes complex signalingdifficult

Communication




Passive-aggressive post-it notes of the animal kingodm

Tactile (touch) Communication:

Where one individual touches, rubs, presses, bites, orhitsa body part against another individual.


– Extremely short range – Day or night


– Can be very complex – Particularly used incourtship and combat

Communication


Touch can be used for courtship or combat.

Monogamy

Individual only has one mate.– Often associated with biparental care– Rare in herps (as well as all other vertebrates)

Mating Systems and Reproduction




Mono: 1 to 1

Polygyny

Single male mates with multiple females– Drives sexual dimorphism; males evolve sexual ornaments, etc.– Most common mating system in herps

Mating Systems and Reproduction


gyny - female


Single male to many females

Polyandry

Single female mates with multiple males– Drives sexual dimorphism; females evolve sexual ornaments, etc.– Rare in herps

Mating Systems and Reproduction


andry - males; multiple

Polygamy

Both males and females mates with multiple individuals.

Mating Systems and Reproduction


Many to many

Operational Sex Ratio (OSR)

The ratio of sexually mature males to fertilizable females atany given time.

Mating Systems and Reproduction




Sexually mature males to fertilize females.

Sexual Reproduction; Pros/Cons

Pros:Gene swapping creates diversity! Prepares fora changingenvironment – the greater the diversity, the better thechances that some offspring will survive the longterm




Cons:Only½ of your genes go into your offspring, colonization of new habitats is not easy.

Mating Systems and Reproduction


-Diversity!


-Only half of ur stuff goes to ur offspring

Unisexual reproduction Pro/Cons

Pros: Fast! All individuals can make offspring. – Colonization of new habitats is relatively easy – Great for a stable environment – if individual is well‐suited to environment environment, its clone will be, too.



Cons: No diversity means vulnerable to disease, parasites

Mating Systems and Reproduction


-You're a strong, indipendent creature! No need for a mate


-Annnnd you're just making copies of yourself, along with all your weaknesses.

Parthenogenesis

Unfertilized eggs give rise to viable offspring– Typically clonal (mother is genetically identical tooffspring) .

Mating Systems and Reproduction


Partho = Parent = Same as Parent; clone

Obligate Parthenogen

Cannot reproduce sexually

Mating Systems and Reproduction


I'm obliged, I have no other choice.

Facultative parthenogen

Normally sexual species that can sometimes reproduce unisexually.

Mating Systems and Reproduction

Gynogenesis

Essentially a parthenogenic species that needs the sperm of another species to stimulate their eggs to develop. The sperm is not incorporated into the genome.

Mating Systems and Reproduction


Parthenogenic = cloning

Hybridogenesis

Hybrid individuals (usually females) breed with non‐hybrid individuals.

Non‐hybrid mate (the male) only gets his geneticcontribution in for one generation, and then his genomeis discarded. Hybrids are essentially sperm parasites.

Mating Systems and Reproduction


Hybrids are essentially sperm parasites. Case closed.

Kleptogenesis

Pros of hybridogenesis: – Hybrids may be more robust than parent species – Lets the parental species do the evolving – hybrids just use the genome of their mates!

Cons: – Hybrids need individuals from parent species tobreed with: • If parent species go extinct, so do hybrids • Hybrids cannot colonize new habitats without parentspecies.

Mating Systems and Reproduction


Klepto; keeping/stealing/hoarding




The kleptogens are basically shape‐shiftingsalamanders that pirate the nuclear genomes ofnearby species.

Intrasexual competition

Competition between members of the same sex formating access to members of the opposite sex.– Can be ritualized (e.g., snake wrestling) or simplegrappling and biting (many lizards).

Mating Systems and Reproduction




Intra-within, male vs male for a female.

Courtship

Convincing someone to matewith you.– Can involve extremely complexbehavior, multimodal forms ofcommunication. (Or not)

Mating Systems and Reproduction



Satellite males

Lots of benefits for the male: less energeticallyexpensive, don’t need to maintain and defendaterritory, etc.– Potentiallya bad deal for the female: she can’tevaluate the quality of the male

Mating Systems and Reproduction


– Non‐advertising male intercepts and mates withfemale attracted to an advertising male.

Clutch piracy

Pirate male amplexes a newly released egg mass from a matingpair immediately after release

Mating Systems and Reproduction

Sexual interference

Competing male sabotages courtship ofanother male


i.e. – Interference through female mimicry


Trick the male to drop his sperm capsule first, and make sure the female picks up ur sperm capsule.

Mating Systems and Reproduction




Remember the salamander thing and ninja looting their capsle

Internal fertilization


(who do it)

Amphibians that do it:


Frogs


Salamanders (Males drop sperm capsule, females pick it up)


All caecilians

Mating Systems and Reproduction


some frogs, salamanders and carnelians.

External Fertilization

All extant reptile taxa: you can’t fertilize an egg onceit has a shell!


Almost all frogs do it, a few salamanders

Mating Systems and Reproduction


Most frogs; few sallies


(clutch piracy)

Delayed fertilization

Some female herps can store sperm for a long time aftermating (years, even). Often have specialized sperm‐storagestructures.

Mating Systems and Reproduction

viviparity

Giving live birth


Pros:female has more control overtemperature of developing young, nest predation isn’t an issue


Cons: cost of carrying around young maybe considerable, if something happens to themother, all young are lost

Mating Systems and Reproduction




Live birth is black magic!

Oviparity

Lays eggs

Mating Systems and Reproduction

Parental care

Any kind of post‐ovipositional/delivery behaviorof the parent(s) that increases the survival of theoffspring; relatively uncommon in herps.

Mating Systems and Reproduction


It's uncommon in herps

Temperature-dependent sex determination

Sex in some reptiles is determined by theincubation temperature of the eggs.

Mating Systems and Reproduction

Habitat loss/modification

Habitatloss/modification isthe largest cause ofherp declinesworldwide

Conservation Topics:

Human population impacts

As human populationincreasesexponentially, demandfor land and generalglobal impact alsoincrease

Conservation Topics:

Species vs ecosystem conservation

In order to preservea species or an ecosystem,need public and political political support; support; species species tend tobe more charismatic than land

Conservation Topics:

The Endangered Species Act (ESA)

Established in 1973, ESA protects listed species fromhuman encroachment/persecution




However, the corruption is real.

Conservation Topics:

Edge effect

Habitats grade into each other. Edges havedifferent characteristics and often do not supportthe same communities.

Conservation Topics:

Habitat fragmentation

turning one large patch ofhabitat into several smaller ones.

Conservation Topics:

Minimum viable population (MVP)

number of individuals needed to havea 99% chance of survival ofa population for1000 years and avoid extinction due todemographic, genetic genetic, or environmental environmentalstochasticity.

Conservation Topics:




99% chance of survival over 1k years

Threats to persistence of small populatiopns

Demographic stochasticity: – Changes in population size – Changes in sex ratio


Genetic stochasticity: – Founder’s effect – Genetic Genetic drift (loss of alleles) alleles) – Inbreeding depression – Outbreeding depression(coming up)– Population bottleneck


Environmental stochasticity:– Catastrophes, climate change,disease, parasites, predators

Conservation Topics:

Minimum dynamic area (MDA)

Minimum Dynamic area


MDA= the amount ofhabitat necessary tomaintain the MVP ofaspecies.



Conservation Topics:




Minimum area to suffice the MVP

Reserves

Reserves, while critical for persistence of many species,are fundamentally fragments of formerly larger habitats.


When creatinga reserve,must be aware of naturalhistory ofspecies/ecosystem(including MVP& MDA) tomake informed decisions

Conservation Topics:




Be aware of the species and preexisting ecosystem

Biological corridors

The idea is that instead of setting asidea large reserve,can have numerous small ones that are connected vianarrow passageways for wildlife.


Problems: – Species Species with low dispersal dispersal abilities abilities may not be able to findand use the corridors.– Often high mortality along corridors. – May be a high concentration of predators at the corridors.

Conservation Topics:




Animal highway! AKA Bottleneck

Captive breeding

The idea is to buy some extra time for a species; if captive‐bred eggs/juveniles have a high survival rate, may generatemore individuals relatively quickly.

Conservation Topics:




Better here than in the wild.

Trans location of herps

Moving threatened herps from one location to another.


With some herps, relocating them can be like a death sentence.

Conservation Topics:




Don't move them away from their homes!

Overharvesting of herps

3 basic categoriesfueling herp harvesting:– Consumption (food, folk medicine)– Luxury trade (leathers, jewelry, curios)– Pet trade

Conservation Topics:


Eating


Trading


pets

Illegal herp trade

Provides endangered herps as pets, highly sought‐afterfood items, folk medicine preparations, and luxury items.


Herps are small, and quiet and don't require much.

Conservation Topics:




They're quiet and fit in small spaces easily and don't require much food.

Herps as food

Approximately 0.2‐1 billionfrogs sold for food every year.• Has led to herp populationcollapses worldwide.• Poorly regulated industry,known to spread diseaseamong amphibians

Conservation Topics:




Disastrous among the amphibians, poor regulation

Invasive species

a species established ina new location by humanswhere it causes ecological and/or economic damage.


Problems:


Inadequate legislation does little to deter possession or activeintroduction of non‐native species.– Limited funding undermines control of incipient populations ofinvasives.– Lack of public awareness: most people can’t identify native vs. non‐native species, don’t recognize importance.– Herp trade lobbyists push for lax regulations

Conservation Topics:




Nobody cares about this stuff! That's the problem!

Pollution:

Environmental pollutants canimpact herp populations inseveral ways:– Can be directly toxic: causesillness/death– Can interfere interfere with physiology; physiology; notimmediately lethal, but causesgrowth/developmental problems

Conservation Topics:




It kills 'em good.

Pollution; Exogenous hormones

– A small amount can effect tremendous change– Many different types (e.g., estrogen, testosterone,growth hormone, et ) c.– Critical to normal growth and development. Exposure to hormones at inappropriate times or toexcessive amounts can disrupt reproductivedevelopment.

Conservation Topics:


Exogenous hormones = hormones producedoutside the body.

Disease: chytrid fungus

causes the often lethal diseasechytridiomycosis in amphibians.• Infects the skin of adults, mouthparts of tadpoles. Amphibians Amphibians are only known host of the fungus.


AKA Bd

Conservation Topics:




Also known as Bd, amphibians carry the disease.

Disease Ranavirus

Ranavirus isa group of viral diseases that causesdeath in amphibians AND reptiles


Extremely contagious: infection can result fromcontact lasting only1 second.

Conservation Topics:


First reported in 1960s; widespread die‐offsrecognized in 1990s.

Disease Fibropapillomatosis

Mostly affects green seaturtles• Benign growths mostlyaffect skin, can also affectinternal organs

Conservation Topics:


1st noticed in 1938,became extremelycommon in 1980s and 90s.

Amphibian deformities

Causes unkown


Suspects include: – Parasites – UV radiation – P ll i o ut on – Injury by predaceous dragonfly larvae

Conservation Topics:

Climate effects

Global climate change may be creating optimalconditions for new diseases (e.g., chytrid)


Worldwide temperature changes may negativelyimpact herp species with TSD.

Conservation Topics:

Rattlesnake roundups

In some parts of U.S., rattlesnakes are collected for largefestival‐type events


Rattlesnakes have bounties on them, those that are captured are abused and maltreated.

Conservation Topics: