Chapter 17 + 18 test Flashcards
What was the name of the ship on which Charles Darwin took his 5 year voyage
HMS beagle
Darwin developed a theory of __________ that offered a scientific explanation for the unity and diversity of life, by proposing how modern organisms evolved through descent from common ancestors.
Biological Evolution
Darwin focused on what 3 patterns of diversity
Species vary globally, species vary locally, and species vary over time
Darwin noticed that different, yet ecologically similar, species inhabited separated, but ______________, habitats around the globe
ecologically similar
Darwin noticed that different, yet related, species often occupied _______________ within a local area
Different Habitats
In addition to collecting specimens of living species, Darwin also collected __________, preserved remains or traces of ancient organisms.
fossils
Darwin noted that the ______________ included many extinct animals that were similar to, yet different from, living species.
fossil record
___________ and ______________ concluded that the earth is extremely old and that the processes that changed Earth in the past are the same processes that operate in the present.
Hutton and Lyell
This way of thinking, called _____________, holds that the geological processes we see in action today are the same processes that shaped Earth millions of years ago.
uniforimtarianism
___________ suggested that individual organisms could change during their lifetimes by selectively using or not using various parts of their bodies. He also suggested that individuals could pass these ______________ on to their offspring, enabling species to change over time
Lamarck/ acquired traits
Today, we know that Lamarck’s hypotheses are completely __________
unsupported
Malthus reasoned that if the human population grew unchecked, there wouldn’t be enough ______________ and __________ for everyone
living space/ food
In ____________________, nature provides the inherited variations, and humans select those variants they find useful.
artificial selection
Darwin’s contribution was to describe a natural process, a scientific mechanism, that could operate like artificial selection. In __________________, he supported his ideas with arguments from Malthus and Lamarck
On the Origin of Species
Any heritable characteristic that increases an organism’s ability to survive and reproduce in its environment is called an ______________
adaptation
________________ describes how well an organism can survive and reproduce in its environment.
Fitness
Individuals with adaptations that are well suited to their environment can survive and reproduce and are said to have high fitness. Individuals with characteristics that are not well suited to their environment either die without reproducing or leave relatively few offspring and are said to have low fitness. This results in differential reproductive success, or, as some call it,_________________
Survival of the Fittest
________________ is the process by which organisms in nature with variations most suited to their local environment survive and leave more offspring.
natural selection
According to the ___________________, all species-living and extinct-are united by descent from ancient common ancestors, and exhibit diversity due to natural selection and adaptation.
Principle of common descent
____________ is the study of where organisms live now and where they and their ancestors lived in the past
biogeography
Patterns in the __________ of _________ and living species, combined with information from geology, tell us how modern organisms evolved from their ancestors.
Distribution/ fossils
_______________ explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.
Evolutionary theory
_____________ are inherited from ancestors, but have lost much of their original size and function.
Vestigial Structures
Body parts that serve similar functions, but do not share structure and development, are called ________________
analogous structures
Similar patterns of _______________ development provide further evidence that organisms have descended from a common ancestor.
Embrylogical
At the ______________ level, overwhelming similarities in the genetic code of all organisms, along with homologous genes and molecules, provide evidence of common descent.
molecular
Many scientific advances have confirmed and expanded Darwin’s hypothesis. Today, __________ is vital to all biological and biomedical sciences, and is often called the grand unifying theory of the life sciences.
Evolutionary theory
In genetic terms, a __________ is a group of individuals of the same species that make and produce offspring
population
A _____________consists of all genes present in a population, including all alleles for each gene
Gene pool
The number of times an allele in a gene pool, as a percentage of the total occurence of all alleles for that gene pool, is called _____________
allele frequency
What are the 3 main ways that genetic variation is produced
Sexual Reproduction, altering of one gene number or position, and formation of new alleles
A trait controlled by one gene that has two alleles is a _________ trait
multiple alleles
Many traits are controlled by two or more genes and are called ______________
Polygenic Inheritance
Natural Selection on single-gene traits can produce changes in allele frequencies that may be reflected by single changes in _______________
phenotype frequencies
Natural Selection on polygenic traits can affect the relative fitness of phenotypes in three types of selection:what are they
directional selection, stabilizing selection, or disruptive selection
What is the change in the frequency of an existing gene variant
Genetic Drift
What are the five conditions that can disturb genetic equilibrium and cause evolution to occur
Mutation, gene flow, small population, nonrandom mating, and natural selection
What is prezygotic barrier that prevents interbreeding, between closely related species
Behavior isolation
When does geographic isolation occur
After natural disasters, phenomenon or something that separates their habitats
A third isolating mechanism, known as ___________, happens when two or more species reproduce at different times
Prezygotic barriers
Speciation in Galapagos finches occured by the founding of a new population, ___________, changes in the new populations gene pool, behavioral isolation, and ____________
Geographical isolation/ ecological Competition
One way new genes can evolve is through, ___________, followed by ___________, of existing genes
Duplications/ modifications
Are chromosomes static DNA sequences
No
A group of regulatory genes known as _______________ determines which parts of an embryo develop into arms,legs, or wings
hox genes
Small changes in Hox gene activity during ______________ can produce large changes in adult animals
embryological devolpment
A __________ uses mutation rates in DNA to estimate the time that two species have been evolving independently
Molecular clock
