Bio Chapter 16 Flashcards
Define: Evolution
change over time: the process by which modern organisms have descended from ancient organisms.
Define: Fossil
preserved remains or traces of ancient organisms
Define: Artificial Selection
selective breeding of plants and animals to promote the occurrence of desirable traits in offspring.
Define: Adaptation
heritable characteristic that increases an organism’s ability to survive and reproduce in an environment.
Define: Fitness
how well an organism can survive and reproduce in its environment.
Define: Natural Selection
Process by which organisms that are most suited to their environment survive & reproduce most successfully; also called survival of the fittest.
Define: Biogeography
study of the past and present distribution of organisms
Define: Homologous Structure
structures that are similar i different species of common ancestry
Define: Analogous Structure
body part that share a common function, but not structure
Define: Vestigial Structure
structure that is inherited from ancestors but has lost much or all of its original function
What was Charles Darwin’s contribution to science?
Darwin developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through decent from common ancestors.
What ideas were changing in the scientific community at the time of Darwin’s travels? How might those new ideas have influenced Darwin?
Geologist were suggesting that earth was ancient and had changed over time. Biologists were suggesting that life on Earth also changed. Those ideas introduced evolution and Darwin is the one who finds out how organisms evolved.
List the three patterns of biodiversity that Darwin noted.
#1: Species vary globally #2: Species vary locally #3: Species vary over time
Darwin found fossils of many organisms that did not resemble any living species. How might this finding have affected his understanding of life’s diversity?
That even though some organisms evolved to be able to live longer, some organisms don’t and they die.
1: Species vary globally (ex. of pattern)
Rheas(grasslands of S. America), Ostriches(Africa) & Emu(Australia): Ground-dwelling birds that can’t fly
2: Species vary locally (ex. of pattern)
2 species of rheas in S America. One in Argentina’s grasslands and other in colder, harsher grass and scrubland to the south.
Galapagos tortoises: each island=different shells
3 Species vary over time (ex. of pattern)
some of the fossils look like modern animals. Giant armored animal that is now extinct (glyptodont) looks a lot like the modern day armadillo, but armadillo =smaller
Summarize the conclusions drawn by Hutton about Earth’s history.
Hutton concluded that Earth is extremely old and that the process that changed Earth in the past are the same processes that operate in the present.
Describe Lyell’s uniformitarianism.
That that laws of nature are constant over time and that scientists must explain past events in terms of processes they can observe in the present. That the geological processes that we see today are the same ones that shaped the Earth millions of years ago.
How did Lamarck propose that species evolved?
He proposed that organisms could change during their lifetimes by selectively using or nor using various parts of their bodies. He also suggested that individuals could pass these acquired traits onto their offspring, enabling species to change over time.
What was Malthus’s view of population growth?
He reasoned that if the human population grew unchecked, there wouldn’t be enough living space and food for everyone.
Under that conditions does natural selection occur?
It occurs in any situation in which more individuals are born than can survive (the struggle for existence), there is natural heritable variation (variation and adaptation), and there is variable fitness among individuals (survival of the fittest).
What does Darwin’s mechanism for evolution suggest about living and extinct species?
According to the principle of common descent, all species-living and extinct-are descended from ancient common ancestors
What do evolutionary trees show? What does a tree of life imply about all species living and extinct?
it shows that all organisms are related. that all organisms share the same common ancestors.
How does the geographical distribution of species today relate to their evolutionary history?
Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors.
Explain how fossils and the fossil record document the descent of modern species from ancient ancestors.
Many recently discovered fossils form series that trace the evolution of modern species form extinct ancestors.
Describe what homologous structures and embryology suggest about the process of evolutionary change.
evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.
Explain the difference between homologous and analogous structures. Which are more important to evolutionary biologists? Why?
H: structures that are similar in different species of common ancestry
A:Share bod parts that have common function but not structure
H, cuz they have the same ancestor
How do the Grants’ data show that genetic variation is important in the survival of a species?
The Grants have documented that natural selection takes place in wild finch population frequently, and sometimes rapidly.
