Chapter 5 - Macroevolution Flashcards Preview

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Flashcards in Chapter 5 - Macroevolution Deck (32)
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1

Classification

In Biology,the ordering of organisms into categories, such as orders, families, and genera, to show evolutionary relationships.

2

Chordata

The phylum of the animal kingdom that includes vertebrates.

3

vertebrates

Animals with segmented, bony spinal columns; includes fishes, amphibians, reptiles (including birds), and mammals.

4

homologies

Similarities between organisms based on descent from a common ancestor.

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analogies

Similarities between organisms based strictly on common function, with no assumed common evolutionary descent.

6

homoplasy

(homo, meaning “same,” and plasy, meaning “growth”) The separate evolutionary development of similar characteristics in different groups of organisms.

7

evolutionary systematics

A traditional approach to classification (and evolutionary interpretation) in which pre- sumed ancestors and descendants are traced in time by analysis of homologous characters.

8

cladistics

An approach to classification that attempts to make rigorous evolutionary interpretations based solely on analysis of certain types of homolo- gous characters (those considered to be derived characters).

9

ancestral

Referring to characters inherited by a group of organisms from a remote ancestor and thus not diagnostic of groups (lineages) that diverged after the character first appeared; also called primitive.

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clade

A group of organisms sharing a common ancestor. The group includes the common ancestor and all descendants.

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derived(modified)

Referring to characters that are modified from the ancestral condition and thus diagnostic of particular evolutionary lineages.

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shared derived

Relating to specific character traits shared in common between two life-forms and considered the most useful type of characteristic for making evolutionary interpretations.

13

phylogenetic tree

A chart showing evolutionary relationships as determined by evolutionary systematics. It contains a time component and implies ancestor–descendant relationships.

14

cladogram

A chart showing evolutionary relationships as determined by cladistic analysis. It’s based solely on interpretation of shared derived charac- ters. It contains no time component and does not imply ancestor-descendant relationships.

15

biological species concept

A depiction of species as groups of individuals capable of fertile interbreeding but reproductively isolated from other such groups.

16

speciation

The process by which a new species evolves from an earlier species. Speciation is the most basic process in macroevolution.

17

sexual dimorphism

Differences in physical characteristics between males and females of the same species. For example, humans are slightly sexu- ally dimorphic for body size, with males being taller, on average, than females
of the same population. Sexual dimor- phism is very pronounced in many spe- cies, such as gorillas.

18

intraspecific

Within species; refers to variation seen within the same species.

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interspecific

Between species; refers to variation beyond that seen within the same species to include additional aspects seen between two different species.

20

paleospecies

Species defined from fossil evidence, often covering a long time span.

21

genus

(pl.,genera)A group of closely related species.

22

ecological niche

The position of a species within its physical and biological environments. A species’ ecological niche is defined by such components as diet, terrain, vegetation, type of predators, relationships with other species, and activity patterns, and each niche is unique to a given species. Together, ecological niches make up an ecosystem.

23

fossils

Traces or remnants of organisms found in geological beds on the earth’s surface.

24

mineralization

The process in which parts of animals (or some plants) become transformed into stone-like structures. Mineralization usually occurs very slowly as water carrying minerals, such as silica or iron, seeps into the tiny spaces within a bone. In some cases, the original minerals within the bone or tooth can be completely replaced, mol- ecule by molecule, with other minerals.

25

taphonomy

The study of how bones and other materials come to be buried in the earth and preserved as fossils.

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geological time scale

The organization of earth history into eras, periods, and epochs; commonly used by geologists and paleoanthropologists.

27

continental drift

The movement of continents on sliding plates of the earth’s surface. As a result, the positions of large landmasses have shifted drastically during the earth’s history.

28

epochs

Categories of the geological time scale; subdivisions of periods. In the Cenozoic era, epochs include the Paleocene, Eocene, Oligocene, Miocene, and Pliocene (from the Tertiary Period) and the Pleistocene and Holocene (from the Quaternary Period).

29

placental

A type(subclass)of mammal. During the Cenozoic, placentals became the most widespread and numerous mammals and today are represented by upward of 20 orders, including the primates.

30

heterodont

Having different kinds of teeth; characteristic of mammals, whose teeth consist of incisors, canines, pre-molars, and molars.