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38 Cards in this Set
- Front
- Back
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How is macro evolution defined?
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• (Macro)evolution – evolution at or above the species level/ The branching of new species from existing species
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Macro evolutionary events include speciation. What is speciation?
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Speciation:
- Birth of a new species - Main event underlying macroevolution |
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What is the biological Species Concept?
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- Group of organisms who can successfully reproduce (i.e. have fertile offspring) in nature and are reproductively isolated from other groups
Share anatomical traits (larger brain in humans; longer legs Share behavioral traits (speech; bipedalism) |
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Explain isolation mechanism: geographical isolation
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Water, mountains, desert can interrupt gene flow
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Another speciation is:
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• A complete interruption: divergence in genetic due to mutations; anatomical (due to adaptation to different environments) which leads to reproductive isolation (successful reproduction is no longer possible) = leads to 2 different species / Species A and Species B. This is also called speciation!
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Explain isolation mechanism: behavorial isolation
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sexual/mating rivals) barriers. Ex. Diet, activity patterns (diurnal vs. nocturnal) can interrupt gene flow
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Explain isolation mechanism: physiological isolation
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Different chromosomal count; size of sexual organs
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Reproduce isolation:
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•Occurs when gene flow is completely interrupted
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Define adaptive radiation:
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-Increase in the number of individuals and their subsequent specialization to different environments (or ecological niches)
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How does invasion of a previously uninhabited area cause adaptive radiation?
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B/C organisms exploit new environments or their environments in a new way. And form colonization of “new” geographical areas
-area where there is little competition and/or little predation [Ex.] Island Galapagos finches, lemurs |
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What is Pseudo-(phyletic) extinction?
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The ancestral group disappears, but has modern descendants
Ex. Dinosaurs ancestral to modern birds |
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What is True extinction?
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It is (more common). When ancestral group dies out, leaving no modern descendants
Ex. Saber-tooth cats, most dinosaurs, dodo bird |
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What is phyletic gradualism?
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* It is a rate of evolution.
* A concept from Darwin & Wallace -Organisms in general change very slowly and gradually/ species emerge slowly -Gaps in the fossil record and missing records -Intermediate types should be found |
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What is punctuated Equilibrium?
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* It is a rate of evolution.
* A concept from Gould & Elderedge -rapid change, then “stasis”: stability/little or no change -Species mostly emerge rapidly or go extinct -Gaps in the fossil record / period of rapid change -Few intermediate types |
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Why do anthropologist study the fossil record?
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•understand a group’s phylogeny (or evolutionary story)
•understand how, where, when adaptations evolved •know about organisms that are now extinct |
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What is a fossil?
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-Remnants or traces of past life.
Ex. Mummy, skeletal remains, teeth |
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The most common types of fossils are:
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bones and teeth
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Why do we end up with so few fossils?
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•Preservation is affected by:
-predation (destroys soft tissues, and bones) -bacterial action (destroys soft tissues too, such as rotting or decay) -wind & water action – cause weathering, scatter pieces -soil chemistry, sediment pressure (destruction of bones or distortion of such things) |
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Taphonomy is:
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History of an organism from its death until its found
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Ice man is important because:
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He was the most oldest preserved body ever found
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Pre-cambrian era:
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2.5 - 4.6 billions years.
1ST APPEARANCE OF LIFE -Prokaryotic life only (bacteria) - |
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Paleozoic era:
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245-505 mya (1st Era)
APPEARANCE OF 1ST VERTEBRATES -fish, amphibians, reptiles, coal swamps |
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Mesozoic era:
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65-245 mya (2nd Era)
-Adaptive radiation of mammals -Adaptive radiation of flowering plants -Marine reptiles; dolphins -Turtles |
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Cenozoic era:
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1.8-65 mya (3rd Era)
-Origin of primates -1st monkeys -1st whales -1st humans |
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Which era mostly occur in mammals?
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In the mesozoic era
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What factors explain why mammals went through adaptive radiation?
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Because they had to adjust to flowering plants, and new environments other than swamps. And more food is available to mammals to eat.
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Continental drift is:
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The movement of continents. It affects plants and animals because they have to adapt to the different environment changes.
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Define stratigraphy:
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the study of the relationships between geological layers
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Define law of superstition:
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an undisturbed context, lower layers are older than the ones above them because they were deposited first
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What is the diff b/t relative and chronometric dating techniques:
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-Relative dating techniques tells us how old fossils or sediments are, relative to other fossils sediments
-There are two methods: Rock Stratigraphy •Like sediments = same age Bio Stratigraphy •Comparison to fossils ----------------------------------------- -Chronometric dating techniques give us an age in number of years. Reference calendric system |
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What is radio active decay?
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unstable isotope decays into a stable one (radioactive decay) at a set rate (given by the half life)
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BCE, CE, BP
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BCE = before the Common Era
AD = Anno Domine We now use CE = Common Era BP = before present Present = 2009 |
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Humans are classified as:
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Primates, Antrhopoids, Catarrhines, Hominoids
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Eocene 37-58 mya
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origin of primates.
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Paleocene 58068 mya
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adaptations first appeared
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Humans are classified as:
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Primates, Antrhopoids, Catarrhines, Hominoids
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Eocene 37-58 mya
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origin of primates.
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Paleocene 58068 mya
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adaptations first appeared
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