ANTH 1000 - Ch. 6 Flashcards Preview

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Flashcards in ANTH 1000 - Ch. 6 Deck (21):
1

macroevolution

evoluation above the species level

2

speciation

the process of forming new species

3

isolating mechanism

a factor that separates bredding populations, thereby preventing gene flow, creating divergent subspecies and ultimately (if maintained) divergent species

4

cladogenesis

speciation through a branching mechanism whereby an ancestral population gives rise to two or more descendant populations

5

heterochrony

change in the timing of developmental events that is often responsible for changes in the shape or size of a body part

6

homeobox gene

a gene responsible for large-scale effects on growth and development that are frequently responsible for major reorganization of body plans in organisms

7

punctuated equilibria

a model of macroevolutionary change that suggests evolution occurs via long periods of stability or stasis punctuated by periods of rapid change

8

anagenesis

a sustained directional shift in a population's average characteristics

9

derived

characteristics that define a group of organisms and that did not exist in ancestral populations

10

ancestral

characteristics that define a group of organisms that are due to shared ancestry

11

convergent evolution

in biological evolution, a process by which unrelated populations develop similarities to one another due to similar function rather than shared ancestry

12

continental drift

according to the theory of plate tectonics, the movement of continents embedded in underlying plates on the earth's surface in relation to one another over the history of life on earth

13

adaptive radiation

rapid diversification of an evolving population as it adapts to a variety of available niches

14

preadapted

possessing characteristics that, by chance, are advantageous in future environmental conditions

15

homeotherm

an animal that maintains a relatively constant body temperature despite environmental fluctuations

16

isotherm

an animal whose body temperature rises or falls according to the temperature of the surrounding environment

17

k-selected

reproduction involving the production of relatively few off-spring with high parental investment in each

18

r-selected

reproduction involving the production of large numbers of offspring with relatively low parental investment in each

19

arboreal hypothesis

a theory for primate evolution that proposes that life in the trees was responsible for enhances visual acuity and manual dexterity in primates

20

visual predation hypothesis

a theory for primate evolution that proposes that hunting behavior in tree-dwelling primates was responsible for their enhanced visual acuity and manual dexterity

21

molecular clock

the hypothesis that dates divergences among related species can be calculated through an examination of the genetic mutations that have accrued since the divergence