Week 7: History of Evolutionary Thought 2 Flashcards
Be sure to review the questions on the slides for practice
what is the tree of life
Illustrates how different lineages evolve from a common ancestor
Showed the world that all species on Earth are related
Groups based on shared traits (patterns of nature)
Darwin established
what is homology
Homology, in biology, refers to the similarity in structure, function, or origin of different biological features, such as anatomical structures, genes, or proteins, in different species due to shared ancestry.
what did darwin argue in regards to homolosy
Darwin argued that organisms share many homologies, some apparent only at the embryonic stage, but still indicating a common ancestor
Darwin and ____________ proposed natural selection as a driver of evolution
Wallace
Briefly explain ALFRED RUSSELL WALLACE upbringing
came from humble beginnings and learned the land surveyor trade, as well as being a teacher.
set off with a naturalist friend to Amazonia (S.A) to make collections, take notes, and become famous!
collections were destroyed at sea by a fire
continue to the Malay Archipelego later, to collect again, and continue his scientific work.
greatly admired Charles Darwin and had read the Voyage of the Beagle.
sent Darwin a letter from Malaysia in 1858, explaining his ideas
Darwin then arranged a meeting of the Linnean Society in London, where the idea of natural selection was presented as a co-discovery between him and Wallace.
The theory of natural selection is based on the premise that…
the world is a tough place to live, and those individuals that cope best will reproduce most.
what are some factors of natural selection
environmental factors
limited resources
time
Ernst Haeckel
Promoted and popularised Darwin’s work, but actually believed in Lamarckism (acquired traits) as opposed to natural selection.
Haeckel was famous for proposing that the development of the embryo of an animal, from fertilization to gestation or hatching (ontogeny), goes through stages resembling or representing successive adult stages in the evolution of the animal’s remote ancestors (phylogeny).
his thinking was wrong
Modern Evolutionary Theory
All of life is descended form a common ancestor.
Organisms inherit traits from their ancestors.
These traits are passed on in the form of DNA molecules.
Traits may be beneficial (good) or deleterious (bad) for individual organisms, enabling others to survive and reproduce more than others. These individuals are considered to be “selected” and have a greater contribution to the next generation. This is called “natural selection” and is a non-random process.
Random survivorship also plays a large role in the evolutionary trajectory of populations and species. These random processes are called “genetic drift”.
As individuals and populations take on new traits and experience new selection pressures, isolation, genetic drift, and other processes, new species are formed.
Species go extinct. As some species go extinct, new opportunities become available for evolving species.
