The French naturalist Lamarck proposed that traits an organism acquires through use or disuse during its life can be passed to its offspring.
Missing Word
Lamarck
Jean-Baptiste Lamarck proposed the inheritance of acquired characteristics. The idea was later discredited, because changes gained during a lifetime are not encoded in genes and are not inherited.
Category: Darwin and Natural Selection
Question 2
The geologist Charles Lyell popularized the view that Earth's features were shaped by slow, gradual processes over vast stretches of time, an idea that strongly influenced Darwin.
Missing Word
Lyell
Charles Lyell built on James Hutton's idea of gradual geological change. Darwin reasoned that if Earth changed slowly over long periods, living species could change gradually too.
Category: Darwin and Natural Selection
Question 3
The naturalist Alfred Russel Wallace, who collected specimens in the Amazon and the Malay Archipelago, arrived at the idea of natural selection independently of Darwin.
Missing Word
Wallace
Wallace and Darwin each developed natural selection on their own, and their papers were presented together to the Linnean Society in 1858.
Category: Darwin and Natural Selection
Question 4
Darwin's book On the Origin of Species was first published in 1859.
Missing Word
1859
Darwin published On the Origin of Species in 1859, a year after his and Wallace's joint papers were presented, laying out the evidence for descent with modification by natural selection.
Category: Darwin and Natural Selection
Question 5
An adaptation is a heritable trait that helps an organism survive and reproduce in its present environment.
Missing Word
adaptation
An adaptation is a heritable feature that natural selection has favored because it improves survival and reproduction under current conditions. If the environment changes, the same trait may no longer be favored.
Category: Darwin and Natural Selection
Question 6
The Austrian monk Gregor Mendel worked out the basic rules of inheritance in pea plants, but his results went largely unnoticed until they were rediscovered in the early 1900s.
Missing Word
Mendel
Mendel published his work in 1866. Once rediscovered, his rules of inheritance were combined with natural selection in the modern synthesis.
Category: Population Genetics
Question 7
The principle that allele frequencies stay constant in the absence of evolutionary forces is named for the mathematician Godfrey Hardy and the physician Wilhelm Weinberg.
Missing Word
Weinberg
Hardy and Weinberg independently showed that allele and genotype frequencies remain steady unless selection, mutation, drift or gene flow acts, giving biologists a baseline for detecting evolution.
Category: Population Genetics
Question 8
When every individual in a population carries the same allele for a gene, that allele is said to have reached fixation.
Missing Word
fixation
Fixation means an allele has a frequency of 1, so no other variant of that gene remains in the population. Drift or selection can drive an allele to fixation.
Category: Population Genetics
Question 9
The study of how an organism's anatomy develops from a fertilized egg into its adult form is called embryology.
Missing Word
embryology
Embryology compares development across species. Shared embryonic features, such as structures that form in early embryos of related species and then disappear before adulthood, are evidence of common ancestry.
Category: Evidence of Evolution
Question 10
The study of the geographic distribution of organisms across Earth is called biogeography.
Missing Word
biogeography
Biogeography examines where species live and why. Patterns such as related groups on continents that were once joined are best explained by evolution combined with plate movement.
Category: Evidence of Evolution
Question 11
A species that occurs naturally in one place and nowhere else in the world is described as endemic.
Missing Word
endemic
Endemic species are typical of isolated islands, such as the Galapagos and Hawaii, where populations evolved apart from the mainland.
Category: Evidence of Evolution
Question 12
The horse lineage branched many times, but today only a single genus, Equus, survives, including domestic horses and Przewalski's horse.
Missing Word
Equus
Equus is the one living genus of the horse family. The fossil record shows many other branches of the lineage that ended in extinction.
Category: Evidence of Evolution
Question 13
The formation of two or more new species from one ancestral species is called speciation.
Missing Word
speciation
Speciation is the splitting of one species into descendant species that are reproductively isolated from one another, either after geographic separation or within one area.
Category: Speciation
Question 14
The condition in which a cell or organism has more than two complete sets of chromosomes is called polyploidy.
Missing Word
polyploidy
Polyploidy means extra whole sets of chromosomes. A polyploid plant often cannot breed successfully with its ancestors, so it can form a new species in a single generation.
Category: Speciation
Question 15
In science, a hypothesis is a tentative explanation that is still being tested, whereas a theory has withstood repeated attempts to disprove it.
Missing Word
hypothesis
A hypothesis is a testable, provisional explanation. A scientific theory, such as evolution, is a well-supported explanation backed by a large body of evidence, not a guess.
Category: Misconceptions About Evolution