SMOKIN NOTES TOP TEN THINGS TO KNOW quiz

In a population of trees, researchers observe a gradual shift in leaf size and shape over a long period. The changes are subtle and occur incrementally from one generation to the next, with no sudden leaps or distinct periods of rapid change. What evolutionary pattern best describes this scenario?

In a population of fish, researchers discover fossil records that show long periods of relatively stable morphology followed by abrupt changes leading to new and distinct forms. The fossil record lacks transitional fossils between these distinct forms. What evolutionary pattern best describes this scenario?

Hardy weinberg requirements are:

In a population of flowers, researchers examine the frequency of a gene responsible for petal color. The gene has two alleles: P (for purple color) and p (for white color). The observed frequencies deviate from what is expected under the Hardy-Weinberg equilibrium. The researchers find that flowers in one part of the meadow preferentially cross-pollinate with nearby flowers of the same color. What condition of the Hardy-Weinberg equilibrium is not being satisfied in this scenario?

5 Hardy Weinberg requirements: MUST have 2 things and CAN'T have 3 things: Must have (1)random mating and (2)large population, CAN'T HAVE mutation, gene flow, natural selection

If all 5 conditions for the Hardy Weinberg equilibrium are being met, then the population isn't evolving.

If any of the 5 conditions of the Hardy-Weinberg equilibrium theory are not being met, then microevolution could be happening.

The failure to meet any of the 5 requirements of the Hardy Weinberg equilibrium theorem could cause microevolution. For example, Hardy Weinberg requires random mating. If sexual selection is occurring in a population with respect to mating (so it's not random mating) or if perhaps controlled laboratory breeding is happening (which isn't random mating), then the requirement of random mating isn't happening, and therefore microevolution COULD be happening.

So the 5 requirements of the Hardy Weinberg Equilibrium are things that could cause microevolution. For Example, the lack of random mating could cause microevolution. Gene flow could cause evolution. A small population could cause microevolution (because a small population is more susceptible to genetic drift changes), mutations could cause microevolution, etc...

In natural systems, conditions are never such that the conditions of Hardy Weinberg equilibrium can occur. Hardy Weinberg is theoretical but can't happen in real life.

Which of the following statements about genetic drift is false?

Genetic Drift would be least likely to cause evolution in which of the following?

Of the 3 population graphs: DIRECTIONAL selection is the graph with a peak that favors individuals that vary from average in one direction (2) DISRUPTIVE selection favors individuals that vary in both directions from average like high and low and (3) STABILIZING selection favors the average or middle.

Microevolutions changes genotypes and Macroevolution creates new species.

Microevolution can be defined as:

What is the most common reason for microevolution?

Gene flow decreases genetic differences and makes a population more similar

Genetic Drift makes a population more similar

An example of STABILIZING SELECTION would be when birds with large and small beaks die off from a drought and only birds with average-sized beaks survive.

An example of DIRECTIONAL SELECTION would be when only the insects that are immune to pesticide poison survive to reproduce. The surviving insects are pesticide resistant, and they vary in 1 direction from the average insect (who was killed by the pesticide), so this is DIRECTIONAL SELECTION.

The prickly pear cacti in the 1950s is an example of DISRUPTIVE SELECTION. Americans picked cacti from nature with average spines for their home gardens, leaving the ones with long or short spines in nature. So the cacti left in nature was only long spined or short spined. This selection varied in both directions away from the average average and is called DISRUPTIVE SELECTION.

A problem/limitation with the definition of the biological species concept is:

Name 3 THINGS that control the rate (or tempo) of speciation

The faster the mutation of an organism's genome, the faster the rate of speciation.

What is an example of how rates of selection impact the rate of speciation?

How can rates of environmental change impact rates of speciation (how fast species change)?

Natural selection tends to favor organisms with high reproductive success.

Allopatric speciation is more common in plants and Sympatric speciation is more common in animals.

Per Professor Gillooly, what's the easiest way to define natural selection?

Per Professor Gillooly, what's the easiest way to define evolution?

Remember, the 3 word phrase describing natural selection has to do with reproduction and it's "differential reproductive success."

The 3 word phrase that best describes evolution has to do with the overall concept of the descent/lineage of a changing group of organisms, and it's "descent with modification".

Only individual organisms evolve.

Natural selection works on populations

Sexual dimorphism is when males and females of the same species have differences in appearance, size or other physical traits.

In a population of birds, researchers observe distinct differences in plumage coloration and size between males and females. Male birds exhibit bright and vibrant plumage with long tail feathers, while females have more subdued colors and shorter tails. Both sexes share similar foraging and nesting behaviors. What phenomenon best describes the observed differences in plumage and size between male and female birds in this population?

"Sneaker" male fish, where some of the males of a species of fish are smaller than other males, and sneak to fertilize the female's eggs while the larger unsuspecting males don't notice them, is an example of INTRASEXUAL DIMORPHISM.

What are the key ways that evolutionary relationships can be determined?

When looking at morphological data to establish evolutionary relationships, you should ONLY classify organisms based on HOMOLOGIES ( a structural similarity organisms share DUE TO COMMON ANCESTRY)

When constructing evolutionary relationships, avoid classifying organisms together due to morphological similarities that aren't due to recent common ancestry (such as homoplasies or analogous traits- both not due to recent common ancestry).

In phylogenetics (constructing evolutionary relationships) avoid classifying organisms together based on similarities that are NOT due to common ancestry, such as homoplasy and analogous traits.

A homology is a structural similarity between organisms that comes from common ancestry. A homoplasy is a structural similarity that does NOT come from recent common ancestry but arose due to similar selective pressures.

A HOMOPLASY (structural similarity between organisms NOT due to recent common ancestry) is an example of convergent evolution (or parallel evolution) when similar features independently evolve because of similar selective pressures.

An example of a homoplasy would be the long tongues of armadillos and anteaters (2 species not related by recent ancestors). Both species developed the long tongues independently out of necessity to get the food source available in their different environments. This is convergent or parallel evolution.

What is the best way that a scientist can determine if morphological similarities are homologies (from recent common ancestors) OR homoplasies (morphological similarities not due to shared recent lineage)?

Homoplasies and analogies are not due to common ancestry.

A homoplasy is a similarity in appearance and an analogy is a similarity in function (both not due to recent common ancestry).

An example of a homoplasy is the arm of a human, leg of a dog, flipper of a dolphin and wing of a bird - each used for different functions, but they are similar morphological structures that aren't due to recent ancestry.

Bird wings and the wings on flies have similarity in function (used for flying) but are not due to recent common ancestry. That makes them ANALOGOUS.

Which of the following is correct about how molecular data can determine evolutionary relationships?

Both homologous traits and homoplasies relate to morphological similarities in appearance. The difference is that a homologous trait is due to __________ ancestry, and a homoplasy ____________

Homoplasies and analogous traits are both NOT DUE TO RECENT COMMON ANCESTRY. But how are homoplasies and analogous traits different?