Chapter 1: Adaptation by Natural Selection

Equilibrium

________: A steady state in which the composition of the population does not change.

nineteenth century

Blending inheritance: A model of inheritance, widely accepted during the ________, in which the hereditary material of the mother and father was thought to combine irreversibly in the offspring.

Fecundity

________: The biological capacity to reproduce.

Darwin

Before ________ there was no scientific explanation for the fact that organisms are well adapted to their circumstances.

Morphology

________: The form and structure of an organism; also a field of study that focuses on the form and structure of organisms.

Placental mammals

________: A mammal that gives birth to live young that developed for a period of time in the uterus and were nourished by blood delivered to a placenta.

Marsupials

________: A mammal that gives birth to live young that continue their development in a pouch equipped with mammary glands.

Natural Selection

________: The process that produces adaptation.

Traits

________: A characteristic of an organism.

Species

________: A group of organisms classified together at the lowest level of the taxonomic hierarchy.

Adaptation

________: A feature of an organism created by the process of natural selection.

Convergence

________: The evolution of similar adaptations in unrelated species.

Adaptation

A feature of an organism created by the process of natural selection

Natural Selection

The process that produces adaptation

Blending inheritance

A model of inheritance, widely accepted during the nineteenth century, in which the hereditary material of the mother and father was thought to combine irreversibly in the offspring

Morphology

The form and structure of an organism; also a field of study that focuses on the form and structure of organisms

Equilibrium

A steady state in which the composition of the population does not change

Stabilizing selection

Selection pressures that favor average phenotypes

Traits

A characteristic of an organism

Characters

A trait or attribute of the phenotype of an organism

Species

A group of organisms classified together at the lowest level of the taxonomic hierarchy

Fecundity

The biological capacity to reproduce

Continuous variation

Phenotypic variation in which there is a continuum of types

Ex

Height in humans is an example of continuous variation

Discontinuous variation

Phenotypic variation in which there is a discrete number of phenotypes with no intermediate types

Ex

Pea color in Mendel's experiments is an example of discontinuous variation

Convergence

The evolution of similar adaptations in unrelated species

Placental mammals

A mammal that gives birth to live young that developed for a period of time in the uterus and were nourished by blood delivered to a placenta

Marsupials

A mammal that gives birth to live young that continue their development in a pouch equipped with mammary glands