Module 14 flash cards

Population

A group of individuals of the same species living in the same area and capable of interbreeding.

Evolution

Change in the genetic makeup of a population over generations.

Population thinking

The idea that individuals within a population vary, and evolution acts on this variation rather than on single “ideal” individuals.

Descent with modification

The principle that species change over time and share common ancestors.

Fossil

Preserved remains or traces of organisms that lived in the past.

Fossil record

The collection of all known fossils and their placement in Earth’s rock layers.

Extant

A species that is currently living.

Extinct

A species that no longer exists.

Sedimentary rock

Rock formed from layers of sediment; most fossils are found here.

Geologic time scale

A timeline that organizes Earth’s history based on major geological and biological events.

Transitional feature

A trait found in a fossil that is intermediate between ancestral and descendant groups.

Phylogenetic tree

A branching diagram showing evolutionary relationships among species.

Vestigial trait

A reduced structure that no longer serves its original function.

Genetic homology

Similarities in DNA sequences due to shared ancestry.

Developmental homology

Similarities in embryonic development among different species.

Structural homology

Similar physical structures in different species due to common ancestry.

Artificial selection

Human-directed breeding to enhance desired traits.

Fitness

An organism’s ability to survive and reproduce in its environment.

Adaptation

A heritable trait that increases survival or reproduction.

Natural experiment

A naturally occurring situation that allows scientists to study evolutionary processes.

What is evolution?

Evolution is the change in the genetic makeup of a population over time.

. What is natural selection?

A process where individuals with advantageous traits survive and reproduce more successfully than others.

What are the four postulates Darwin proposed?

1. Individuals in a population vary.

2. Some variations are heritable.

3. More offspring are produced than can survive.

4. Individuals with advantageous traits have higher survival and reproduction.

What are the five types of evidence used to investigate evolution?

1. Fossil record

   • Shows changes in species over time.

2. Biogeography

   • Geographic distribution of species supports common ancestry.

3. Comparative anatomy

   • Homologous and vestigial structures indicate shared ancestry.

4. Embryology

   • Similar early development suggests relatedness.

5. Molecular biology

   • DNA and protein similarities reveal genetic homology.

What are homologous structures?

Structures with similar anatomy due to common ancestry, even if they have different functions.

What are vestigial traits?

Reduced or unused structures inherited from ancestors.

Lamarck’s Theory of Inheritance of Acquired Characteristics

1. Driving Force

   • The idea that organisms change due to use and disuse of traits.

2. Major Downfall

   • Acquired traits are not genetically inherited.

What is the driving force behind Darwin’s theory of natural selection?

Differential survival and reproduction due to heritable variation.

What is the biological definition of fitness?

The ability of an organism to survive and reproduce in its environment.