Natural Selection and Evolution Review

Flashcards covering Charles Darwin's theory of natural selection, historical influences, evolutionary mechanisms, and key evidence for evolution.

What mechanism for evolution did Charles Darwin present?

Natural selection.

What is the full title of Charles Darwin's book published in 1859?

On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life.

On what exact date was Charles Darwin's On the Origin of Species published?

November 24, 1859.

What two major geological concepts were formulated by Hutton and Lyell?

That the earth was several million years old and that the earth had changed during those millions of years.

What mechanism for evolution was proposed by Lamarck?

Inheritance of acquired characteristics, proposing that organisms acquired or lost traits through selective use or disuse of organs during their lifetime and passed them to offspring.

What three main concepts were included in Lamarck's evolutionary hypothesis?

Tendency toward perfection, use and disuse, and inheritance of acquired characteristics.

What did English economist Thomas Malthus propose regarding human population growth?

That if human population growth continued unchecked, there would eventually not be enough resources for everyone.

How is carrying capacity defined in ecology?

The amount of organisms that can be supported by an ecosystem without degrading the environment.

According to Malthusian Population Growth, how do populations grow compared to limiting factors in nature?

Populations grow geometrically, whereas limiting factors stay constant or grow arithmetically.

What were the three main categories of Darwin's observations during his voyage?

Patterns of diversity, living organisms and fossils, and observations at the Galapagos Islands.

How is biological diversity defined?

The degree of species variety and balance in an ecological community.

Where are the Galapagos Islands located, and what key variations did Darwin observe there?

Located west of Ecuador in the Pacific Ocean; Darwin observed that tortoises varied in predictable ways from island to island and birds had different shaped beaks.

Which naturalist considered similarities between humans and apes prior to Darwin?

Buffon.

What is Darwin's Principle of Common Descent?

The principle that species evolved from ancestral species, life is united through descent from a common ancestor, and adaptations accumulate over time.

How did Darwin define natural selection?

The process by which individuals with inherited characteristics well suited to the environment leave more offspring on average than do other individuals.

What is Fact 1 of Darwin's theory regarding species fertility?

Overproduction: all species have such great potential fertility that population size would increase exponentially if all individuals born reproduced successfully.

According to Darwin's Inference 1, what does overproduction lead to in a population?

A struggle for existence among individuals, with only a fraction of offspring surviving each generation.

What three processes generate variation within a species?

Mutations, shuffling of genes during meiosis, and sexual reproduction.

According to Darwin's Inference 2, what determines survival in the struggle for existence?

Survival is not random, but depends in part on inheritable characteristics that give individuals an advantage over others.

According to Darwin's Inference 3, what is the long-term result of unequal survival and reproduction?

A gradual change in a population, with favorable characteristics accumulating over generations.

How is fitness defined in evolutionary biology?

The ability of an organism to survive AND reproduce.

What are adaptations?

Inherited characteristics that increase the fitness of individuals in a population.

What is speciation?

The evolution of one or more new species from a single ancestral species.

What is divergent evolution and what frequently causes it?

A process in which once-related populations evolve independently, often occurring as a result of geographic isolation.

What is geographic isolation?

A condition where two populations are separated by geographic barriers such as rivers or mountains.

What is convergent evolution?

A process in which different species evolve with similar characteristics, often as a result of living in a similar environment.

What is coevolution?

A process where two or more organisms evolve together to match each other's lifestyle or adaptations.

What is artificial selection (selective breeding)?

A process where humans choose how to breed and select organisms based on traits they want to see in offspring.

How is phylogeny defined?

The genetic and evolutionary history of a group of organisms, represented by its hypothesized ancestor-descendant relationships.

What four lines of evidence support evolution according to the lecture notes?

The fossil record, embryology, comparing body structures, and DNA sequences.

According to the fossil record, how old is the oldest evidence of life, and how old are the oldest prokaryote fossils?

The oldest fossil evidence of life is 3.8 billion years old, and prokaryotes are found in rocks 3.5 billion years in age.

What are homologous structures?

Characteristics with similar structure but slightly different functions found in different species, inherited from a common ancestor.

What are analogous structures?

Characteristics shared by different species that are similar in function but not in structure, and are not inherited from a common ancestor.

What are vestigial structures, and what example is seen in snakes?

Unused structures or characteristics that are similar to structures in other species; an example is the spur legs found on snakes.

What is embryology, and how does it provide evidence for evolution?

The study of the growth and development of embryos, where shared features in young embryos suggest common ancestry.

Based on DNA sequence similarity, which species (A: 60%, B: 92%, C: 96%, D: 73%) is most closely related to humans?

Species C, with 96% DNA similarity.