Origin of Species

Question 1

Erasmus Darwin

Answer 1

Charles Darwin’s grandfather, who was the first in the family to propose that life evolves, though without a detailed mechanism

Question 2

Fossil Record

Answer 2

Darwin observed that fossils of extinct animals resembled living species in the same region, suggesting a process of gradual change over time

Question 3

Common Descent

Answer 3

Darwin’s explanation for the similarity between fossils and living species, proposing that they share a common ancestor and have diverged over time through evolution

Question 4

Galapagos Finches

Answer 4

A group of bird species Darwin studied on the Galapagos Islands, whose varying beak shapes fascinated him and contributed to his development of the theory of natural selection

Question 5

Adaptive Radiation

Answer 5

The process by which species evolve rapidly into a variety of forms, as Darwin observed with the Galapagos finches, where different species adapted to different ecological niches

Question 6

Thomas Malthus

Answer 6

An economist whose ideas on population growth influenced Darwin, specifically the concept that organisms compete for limited resources, which led Darwin to the idea of “struggle for existence”

Question 7

Struggle for Existence

Answer 7

The competition among organisms for limited resources, an idea Darwin adapted from Malthus to form a key part of his theory of natural selection

Question 8

Confessing a Murder

Answer 8

Darwin’s metaphor for the guilt he felt in revealing his theory, knowing it would challenge widely held religious and scientific beliefs

Question 9

Delay in Publishing

Answer 9

Darwin delayed publishing On the Origin of Species for over 20 years due to fear of backlash from the scientific community and society, and concern over the controversial nature of his ideas

Question 10

Homologous Structures

Answer 10

Structures in different species that are similar due to shared ancestry, such as a bat’s wing, mole’s foot, and manatee’s fin, despite their different functions

Question 11

Comparative Anatomy

Answer 11

The study of similarities and differences in the anatomy of different species, which helped Darwin support that concept of evolution by common descent

Question 12

Thomas Huxley

Answer 12

A biologist and advocate for Darwin’s theory of evolution, often referred to as “Darwin’s Bulldog” for his vocal defense of natural selection

Question 13

Alfred Russel Wallace

Answer 13

A naturalist who independently conceived the theory of natural selection, prompting Darwin to publish On the Origin of Species

Question 14

Artificial Selection

Answer 14

The process by which humans breed animals or plants for specific traits, as Darwin observed in pigeons. It helped him understand how natural selection operates in the wild

Question 15

Natural Selection

Answer 15

The process by which organisms with advantageous traits survive and reproduce more successfully, leading to gradual evolutionary changes in a population

Question 16

Distinct Species

Answer 16

Darwin argued that despite gradual changes, natural selection leads to the divergence of species into distinct groups because organisms adapt to specific ecological niches

Question 17

Fossilization Likelihood

Answer 17

Darwin recognized that fossilization is a rare event, with only certain parts of animals, typically hard structures like bones, having a chance of becoming fossilized

Question 18

“Half an Eye”

Answer 18

Darwin would argue that even a partially developed eye can be useful, as natural selection favors any trait that provides a survival advantage, no matter how incomplete

Question 19

Evolution in the 1870s

Answer 19

By the 1870s, most British scientists had accepted the concept of evolution, though not all fully embraced natural selection as the mechanism

Question 20

Island Species Fewer Than Mainland

Answer 20

Darwin observed that islands had fewer species than nearby continents, even when accounting for size, challenging the idea that species were divinely placed equally everywhere

Question 21

Lack of Frogs and Toads

Answer 21

Islands often lacked species like frogs, which are well-suited for such environments, suggesting that these species couldn’t naturally reach islands, rather than being placed by a creator

Question 22

Isolation Affects Species Variety

Answer 22

Islands that are harder to reach, due to deep waters or distance from the mainland, had fewer species, which indicated that isolation naturally limits species migration

Question 23

No Land Mammals on Remote Islands

Answer 23

Darwin found no land mammals on islands more than 300 miles from a continent, except for bats, indicating that land mammals face challenges in migrating over such long distances

Question 24

Mainland Relatives of Island Species

Answer 24

Island species often have close relatives on nearby continents, implying migration and evolutionary change after reaching the islands rather than divine placement

Question 25

Mismatch of Species and Environment

Answer 25

Plants with traits suited to environments with mammals, such as hooked seeds for transport by animals, were found on islands without mammals, contradicting the idea of intelligent design

Question 26

Species Outcompeted by Invasive Ones

Answer 26

Endemic island species were often outcompeted by species introduced by humans, which challenges the idea of perfect divine placement and instead suggests natural competition

Question 27

Evolutionary Adaptation

Answer 27

Darwin concluded that the patterns he observed in island species made more sense under the theory of natural evolution rather than intelligent design

Question 28

Biogeographical Insights

Answer 28

The proximity of islands to continents influenced the types of species found there, supporting migration and evolutionary adaptation over divine intervention

Question 29

Evolutionary Explanation More Fitting

Answer 29

Darwin found that evolutionary theory, which accounts for migration and adaptation, provided a better explanation for island species distribution than creationist views

Question 30

Over-Reproduction

Answer 30

All species tend to produce more offspring than can survive, creating a competition for limited resources

Question 31

Heritable Variation

Answer 31

Offspring vary in traits, and some of these traits are passed down genetically from their parents, leading to diversity within populations

Question 32

Limited Resources

Answer 32

Resources like food, water, and shelter are finite, which increases competition among organisms for survival

Question 33

Competition

Answer 33

The struggle for survival due to over-reproduction and limited resources leads to competition among individuals in a species and between species

Question 34

Differential Reproduction

Answer 34

Individuals with advantageous traits are more likely to survive and reproduce, passing their traits to the next generation

Question 35

Gene Pool Shift

Answer 35

Over time, beneficial traits become more common within a population’s gene pool as those with these traits reproduce more

Question 36

Intraspecies Competition

Answer 36

Competition occurs not only between different species but also within the same species as individuals strive to survive and reproduce

Question 37

Selected For

Answer 37

Traits that enhance an individual’s ability to survive and reproduce are “selected for,” leading to greater reproductive success

Question 38

Selected Against

Answer 38

Individuals without advantageous traits are “selected against,” resulting in shorter lifespans and fewer opportunities to pass on their genes

Question 39

Giraffes’ Long Necks

Answer 39

Giraffes have necks up to 6 feet long, supported by the same seven vertebrae found in most mammals, including humans

Question 40

Food Competition Theory (Giraffe Neck)

Answer 40

The theory that longer necks allow giraffes to reach higher branches, giving them access to food that other animals can’t reach, thus providing a survival advantage

Question 41

Necks for Sex Theory

Answer 41

Another theory suggests that male giraffes evolved long necks to fight other males for mating opportunities, a behavior known as “necking”

Question 42

Necking Fights

Answer 42

Male giraffes engage in necking fights where they swing their necks as weapons, and winners gain better access to females, securing more mating success

Question 43

Sexual Selection

Answer 43

This form of natural selection occurs when individuals with certain traits, like long necks in giraffes, are more successful in mating and passing on their genes

Question 44

Gene Transmission in Giraffes

Answer 44

Males with longer necks are more successful in mating, passing their genes for long necks to their offspring, further contributing to neck elongation over time

Question 45

Genetic Basis of Giraffe Necks

Answer 45

Genes controlling neck length and the ability to fight through necking are passed down, resulting in a selective advantage for giraffes with longer necks

Question 46

Sexual Dimorphism in Giraffes

Answer 46

Male giraffes tend to have heavier necks and heads compared to females, likely due to the pressures of necking fights for reproductive success

Question 47

Stephen Jay Gould’s Insight on Giraffe Necks

Answer 47

Gould suggested that while giraffes’ long necks help them reach high food, this may not be the original reason the trait evolved, with sexual selection being a stronger pressure

Question 48

Palmaris Longus Muscle

Answer 48

A muscle present in 86% of humans, located in the forearm, that no longer serves a significant functional purpose in humans today

Question 49

No Negative Impact of Palmaris Longus

Answer 49

The absence of the palmaris longus muscle in 14% of the population has no effect on the grip strength, wrist function, or movement, suggesting it’s a non-essential muscle

Question 50

Vestigial Structure

Answer 50

A structure remnant from evolutionary ancestors but no longer has a crucial function, such as the palmaris longus muscle

Question 51

Palmaris Longus in Primate Evolution

Answer 51

The muscle is inherited from primates like orangutans, who still use it for climbing, reflecting our shared evolutionary history

Question 52

Palmaris Longus is a Neutral Trait

Answer 52

The presence or absence of the palmaris longus muscle does not affect human survival or reproductive success, making it a neutral trait in evolution

Question 53

No Selection Pressure of Palmaris Longus

Answer 53

Since the muscle neither helps nor hinders human reproduction, natural selection has not favored its removal or persistence

Question 54

Modified Muscle Function of Palmaris Longus

Answer 54

Over time, changes in the muscles around the thumb and forearm reduced the importance of the palmaris longus, rendering it functionally obsolete

Question 55

Palmaris Longus in Chimpanzees

Answer 55

Like humans, chimpanzees also have a vestigial palmaris longus muscle, further linking us to common evolutionary ancestors

Question 56

Vestigial Structures Fail Intelligent Design

Answer 56

The existence of a useless muscle, such as the palmaris longus, contradicts the idea of intelligent design, as it serves no purpose in humans

Question 57

Evolutionary Explanation of Palmaris Longus

Answer 57

Evolution explains the persistence of the palmaris longus as a remnant of a once-functional structure in our ancestors, where it played a role in their survival