Biology Test 1

Front 1

Absolute dating

Back 1

Age of fossils is estimated by rates of radioactive decay within fossilized tissue.

Front 2

Adaptation

Back 2

A trait with a current functional role in the life of an organism that is maintained and evolved by means of natural selection

Front 3

Adaptive radiation

Back 3

Closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment. Occurs under special conditions.

Front 4

Aristotle

Back 4

- described all living things known to his world - assumed forms were fixed and immutable.

Front 5

Anaximander

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Thought that forms of life had changed - proposed human origins in sea creatures. - first concept of forms transitioning from ancestor to descendant

Front 6

Lamark

Back 6

Evolution by inheritance of squired characteristics. Lamark's ideas were unconvincing. "Inheritance of acquired traits" was incorrect

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Charles Darwin

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Biological evolution is change in species over time. Not a new idea at the time. No good mechanisms to explain how hear changes occurred. The Origins of Species. Theory of evolution by natural selection

Front 8

Malthus

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The economist Malthus (essay on the principle of population) pointed out that human population growth can exceed the resources necessary to support them.

Front 9

Natural selection

Back 9

Populations change as they adapt to their changing environment; it is all about survival and reproduction.

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Microevolution

Back 10

Changes that occur within a biological population. Easily observed. Noncontroversial. Examples: pesticide resistance in crop-eating insects, Antibiotic resistance in infectious bacteria.

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Macroevolution

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Large-scale evolutionary changes that result in the origin of new species. Occurs slowly over long periods of time. -TYPES of EVIDENCE- artificial selection. Fossils. Anatomical.Embryological. Experimental. Molecular.

Front 12

Artificial selection

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Appearance can change and can be inherited.

Front 13

Fossil record

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Provides record of the course of life through time. Also shows waxing and waning of biological diversity.

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Convergent evolution

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Structural similarities in unrelated species with similar lifestyles. No recent common ancestry. Evolution occurred in parallel in different groups. Examples - bird and bat wings, football- shaped bodies in Tuna and penguins.

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Vestigial structures

Back 15

Organs with no apparent modern function, but resemble ancestral structures.

Front 16

Homologous structures

Back 16

A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor. In other words, it's when very different animals have bones that appear very similar in form or function and seem to be related.

Front 17

Robust

Back 17

A robust theory - good explanation for variety of observations. Well-supported by wide variety of evidence. -anatomy- geology- molecular biology - genetics. Demonstrates consilience: agreement among observations from different sources

Front 18

Robust

Back 18

A robust theory - good explanation for variety of observations. Well-supported by wide variety of evidence. -anatomy- geology- molecular biology - genetics. Demonstrates consilience: agreement among observations from different sources

Front 19

Fixed allele

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Allele is so adaptive that it is present in all of the members of the population

Front 20

Deleterious allele

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Allele, especially in homozygotes, that is so harmful that it is selected against and reaches frequency of zero.

Front 21

Mutation

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Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.

Front 22

Directional selection

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Acts to eliminate one extreme (know charts)

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Disruptive selection

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Acts to eliminate intermediate types. Different beak sizes of African black- bellied seed cracker finch. (Know chart)

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Disruptive selection

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Acts to eliminate intermediate types. Different beak sizes of African black- bellied seed cracker finch. (Know chart)

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Stabilizing selection

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Acts to eliminate both the extremes. Makes intermediate more common by eliminating extremes. (Know chart)

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Reproductive isolation

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Members of different species do not mate with each other nor do they produce fertile offspring.

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Subspecies

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Within a single species, individuals in populations that occur in different areas may be distinct from one another.

Front 28

Prezygotic isolation

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Geographic - 2 similar species are separated from one another by a geographic barrier, such as a river or mountain range. Ecological- geographic ranges overlap but different species utilize different parts of the habitat. Behavioral -certain animal behavior preclude inappropriate species pairings.

Front 29

Postzygotic isolation mechanism

Back 29

Hybrid inviability or infertility

Front 30

Allopatric speciation

Back 30

2 part process - 1. Gene flow must be disrupted by a geographic barrier, leading to isolation of populations. 2. Reproductive isolation must evolve to maintain these differences.

Front 31

Sympatric speciation

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One species splits into two a a single locality, without the 2 new species ever having been geographically separated. - one type occurs commonly as the result of polyploidy another type involved disruptive selection.

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Derived characteristics

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Similarity that is inherited from the most recent common ancestor of an entire group.!

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Primitive characteristic

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Similarity that arose prior to the common ancestor of the group.

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Paleontology

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The study of ancient life. Lies at the junction between biology and geology. Provides record of evolution of life as well as insight into selective pressures of environment.

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Stratigraphy

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Layering of sedimentary and volcanic rock reflects geological history of a region. Biostratigraphy links fossils to geological layers (strata).

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Biogeography

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"The study of what organisms live where on earth and why"

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Plate tectonics

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Mechanism for continental movement.

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Continental drift

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the gradual movement of the continents across the earth's surface. Evidence- biogeography, faunal/floral distribution. Geology - continents and mountain belts fit like puzzles, glacial grooves.

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Uniformitarianism

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Same geological process that affected earth in the past affect earth today and will affect earth tomorrow.

Front 40

Catastrophism

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Opposite of uniformitarianism Past catastrophes were unique.

Front 41

Acquired inheritance

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The inheritance of acquired characteristics is a hypothesis that physiological changes acquired over the life of an organism (such as the enlargement of a muscle through repeated use) may be transmitted to offspring.

Front 42

Binomial

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The binomial nomenclature system combines two names into one to give all species unique scientific names. The first part of a scientific name is called the genus. The second part of a species name is the specific epithet.

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Biological species concept

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The biological species concept defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance. Although appearance is helpful in identifying species, it does not define species.

Front 44

Character displacement

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Character displacement refers to the phenomenon where differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species' distributions do not overlap

Front 45

Evolutionary fitness

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Fitness (often denoted or ω in population genetics models) is a central idea in evolutionary and sexual selection theories. It can be defined either with respect to a genotype or to a phenotype in a given environment

Front 46

Evolutionary reversal

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Evolutionary reversal refers to an inherited trait reverting back to an earlier form over the course of many generations.For instance,whales are an example of evolutionary reversal in that they once were land animals who returned to an aquatic state

Front 47

Founder effect

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The effect on the resulting gene pool that occurs when a new isolated population is founded by a small number of individuals possessing limited genetic variation relative to the larger population from which they have migrated

Front 48

Gene flow

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In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies (the proportion of members carrying a particular variant of a gene)

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Genetic bottleneck

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A population bottleneck is an event that drastically reduces the size of a population. The bottleneck may be caused by various events, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms

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Genetic drift

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The process of change in the genetic composition of a population due to chance or random events rather than by natural selection, resulting in changes in allele frequencies over time

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Gondwana

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is the name given to an ancient supercontinent. It is believed to have sutured between about 570 and 510 million years ago (Mya), joining East Gondwana to West Gondwana. Gondwana formed prior to Pangaea, and later became part of it.[3]

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Hybrid inviability

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Hybrid inviability is a post-zygotic barrier, which reduces a hybrid's capacity to mature into a healthy, fit adult. The relatively low health of these hybrids relative to pure-breed individuals prevents gene flow between species

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Hybrid sterility

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The offspring display traits and characteristics of both parents. The offspring of an interspecific cross are very often sterile; thus, hybrid sterility prevents the movement of genes from one species to the other, keeping both species distinct

Front 54

Neutral variation

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Variation that does not favour any particular genotype.

Front 55

Pangaea

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Pangaea is a hypothetical supercontinent that included all current land masses, believed to have been in existence before the continents broke apart during the Triassic and Jurassic Periods

Front 56

Relative dating

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Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. estimated age