Intro to Evolutionary Theory

Geometry & relationship of _________, ________ _______, and _________ drive the consequences of size.

length, surface area, and volume

Larger animals ---> greater significance of _________

gravity

Smaller animals ----> greater significance of ___________ ________

surface tension

Even if shape remains the same, increases in size changes the _____________ among length, surface, and volume.

proportions

Which increases the most when size changes?

Relative Surface Area

Rate of _____________ _________, diffusion of oxygen from blood to tissues, and gain/loss of body heat rely on relative surface area.

oxygen uptake

As body size increases, oxygen consumption per unit of body mass decreases.

decreases

Smaller animals (e.g., shrews) use ________ oxygen per gram of body weight than larger animals (e.g., elephants).

more

Smaller animals have a higher surface area relative to their volume, meaning they...

Lose heat faster and need a faster metabolism to stay warm.

Homology

features with common ancestry

Analogy

features with similar functions

Homoplasy

features that simply look alike

Evidence of evolution: fossil records theory

Simple organisms in deep layers while complex fossils in shallow layers.

Evidence of evolution: cambrian explosion

- Precambrian: single-celled organisms

- Cambrian: Marine animals

punctuated equilibrium

Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change.

Evidence of evolution: biogeography

Organisms in same area resemble each other (i.e. mainland vs galapagos iguana).

Evidence of evolution: comparative anatomy

Anatomical similarities between species give signs of common descent from an ancestral species.

Evidence of evolution: "Descent with mmodification"

When new species appear in the fossil record, they are not completely reengineered, but result from modifications of an ancestral species.

Evidence of evolution: vestigial structures:

organs with no function (i.e. leftover "legs" on a snake).

Evidence of evolution: Comparative embryology.

Embryonic stages of many organisms are similar. Only during later stages of development of their appearances diverge (i.e. gill pouches found in all the organisms but develop differently).

Evidence of evolution: molecular biology

At biochemical level, every species is similar. Every organism has DNA and codons are identical across species.

Evolution "Myths" - "We are evolving into higher beings" debunking

- Evolution is "directionless"

- Based solely on evolutionary fitness

- Fitness based on ability to pass genes on to next generation.

Evolution "Myths" - "If humans evolved from apes, why are apes still around?" debunking

We had a common ancestor that both apes and humans split off from.