BIOL 1001 Chapter 22 (22.1)

What is evolution?

A heritable change in one or more characteristics of a population from one generation to the next.

Who developed the idea of descent with modification?

Charles Darwin

What voyage influenced Darwin’s ideas about evolution?

The HMS Beagle voyage (1831-1836).

What is adaptive radiation? What is an example?

Evolution of many different species from a common ancestor adapting to different environments, Darwin’s finches is an example.

What did Darwin observe about finch beaks?

Different beak shapes were adapted for different food sources.

What is descent with modification?

Existing species are derived from pre-existing species.

What is natural selection?

Individuals with favorable inherited traits are more likely to survive and reproduce.

What is selective pressure?

A force in the environment that influences whether a trait is beneficial.

Selection happens at the ___ level, but evolution happens over many ____.

Individual; generations.

3 conditions required for natural selection?

Variation exits, variation affects reproductive success, and variation is heritable.

What is a heritable trait?

A trait that can be passed from parent to offspring.

What is artificial selection? What is another name for artificial selection?

Humans selectively breeding organisms for desired traits, another name is selective breeding.

What is the difference between natural selection and selective breeding?

Natural selection is driven by the environment; selective breeding is driven by humans.

Peppered moth is an example that demonstrates what?

Natural selection.

Why did black peppered moths become more common during the Industrial Revolution?

They were better camouflaged on soot-darkened trees.

5 major types of evidence for evolution?

Fossil record, biogeography, convergent evolution, selective breeding, and homologies.

What is a fossil?

Preserved remains or traces of past life.

What does the fossil record show?

Extinction, origin of new groups, and changes within groups over time.

Older rocks usually contain fossils of what type of organisms?

Simpler organisms.

Newer rocks usually contain fossils of what type of organisms?

More complex organisms.

What is transitional form? What an example?

An organism showing traits linking earlier and later groups, an example is Tiktaalik roseae.

Why is the fossil record incomplete?

Many organisms do not fossilize and fossils can be destroyed by erosion or tectonic activity.

What is biogeography?

Study of the geographic distribution of species.

What is endemic species?

Species naturally found only in one specific location.

What is an example of island biogeography from lecture?

Island fox vs gray fox.

What is continental drift?

Movement of Earth’s continents over time.

What is Pangaea?

Ancient supercontinent where Earth’s continents were once connected.

What is convergent evolution? Are species involved in convergent evolution closely related?

Different species independently evolve similar traits because they live in similar environments, no they’re not related.

What are analogous structures? Analogous structures result from what process?

Structures with similar function but different evolutionary origin, result from convergent evolution.

Example of convergent evolution from lecture?

Hummingbird and hummingbird moth.

Example of convergent evolution involving fish?

Sea raven and longhorn sculpin.

What is homology? 3 types of homologies?

Similarity resulting from common ancestry, three types are anatomical, developmental, and molecular.

What are homologous structures?

Structures inherited from a common ancestor.

Homologous structures usually have ___ structure but ___ function.

Similar; different.

What are examples homologous structures?

Vertebrate forelimbs.

What are vestigial structures? Example of vestigial structures in humans?

Structures with reduced or no current function that resemble ancestral structures, examples in humans are tailbone and ear-moving muscles.

What is developmental homology? What is an example of developmental homology in humans?

Similarities in embryonic development among species, examples are gill ridges and a bony tail in embryos.

Convergent evolution vs homology?

Convergent evolution= unrelated species develop similar traits; homology= shared traits from common ancestry.

What are analogous structures vs homologous structures?

Analogous= same function/different structure; homologous=similar structure/different function.

Darwin’s finches demonstrate what?

Adaptive radiation.

Gill ridges in fish and human embroys are an example of what?

Developmental homology.

Wings of butterflies and birds are an example of what?

Convergent evolution/analogous structures.

Kale, broccoli, cabbage, and cauliflower are examples what?

Selective breeding/artificial selection.

Darwin’s theory explains evolution through..?

Natural selection.

Why does variation matter in evolution?

Natural selection can only act on existing variation.

What is Fitness in evolution?

An organism’s reproductive success.

What kind of traits are favored by natural selection?

Traits that increase survival and reproductive success.

What evidence supports continental drift?

Distribution of fossils across continents.

What type of evidence compares DNA and proteins?

Molecular homology.

What type of homology compares body structures?

Anatomical homology.

What type of homology compares embryos?

Developmental homology.