What evidence led to these decisions? There should be at least one line per pair. Salmon & GoldfishGrizzly Bears & Polar BearsSince salmon and goldfish are both fish, they have manyGrizzly bears live in diverse habitats in the norther hemi-traits in common. But they have many differences too.They live in different habitats, they eat different food, theysphere, where they eat a wide array of fruit, plants, andmeat. Polar bears live in frozen lands to the north, wherebehave differently, they have very different anatomy-andthey roam on ice sheets and hunt seals. The two bearsthey never interbreed. A large body of evidence showshave different anatomy and behavior, and they are broadlyconsidered to be different species. DNA analysis estimatesthat they diverged from a common ancestor about 400,000years ago. Yet once in awhile, at the edges of their ranges,they do meet and interbreed. Using genetic testing, re-searchers have identified multiple "grolar bear" hybrids inthat they descended from a common ancestor, yet at somepoint in the distant past, maybe their ancestors weren't sodifferent from one another.the wild.Fly Agaric MushroomsCommon & AustralianBlacktip SharksThese poisonous mushrooms live in many places around theworld. Different populations have different characteristics.Most are red with white spots, but others are yellow, orange,white, tan, or brown. Fly agaric mushrooms reproduceusing spores, which can travel by wind across greatThe common blacktip shark lives in coastal waters aroundthe world. The Australian blacktip shark, which lives offthe coast of northern and eastern Australia, looks almostidentical to the common blacktip-though it is smaller, itdistances. Because they are isolated, with little chance ofinterbreeding, populations living on different continentshave traditionally been considered different species. YetDNA analysis has shown that even populations living inlives in warmer water, it has a different number of ver-tebrae, and it has unique genetic markers. The two typesof sharks were once thought to reproduce only with theirown kind. However, using genetic markers, scientists haveNorth America form genetically distinct groups. Eachfound dozens of sharks off the coast of Australia that aregroup occupies a distinct habitat, and alleles do not mixfreely between them.hybrids between common and Australian blacktips. Same or Different Species?The Species ContinuumBackgroundFor organisms that reproduce with a partner, scientists generally define a species as a group ofinterbreeding individuals that don't breed with other groups. Using this definition, it's sometimes veryclear when two organisms are separate species.Yet we also know that, through natural selection, populations change over time. How much does apopulation have to change before we can call it a new species?Part of the trickiness in defining a species comes from the fact that species do not often form in aninstant. Usually, speciation is a process that happens gradually over long periods of time-typicallythousands or even millions of years. What we can observe is just a snapshot of this process in time.Instructions1. Get a set of Organism cards.2. Read the information on each card, and decide whether you think the organisms described arethe same or different species, or somewhere in between. Look for key information, such as:Do they interbreed?Do they live in the same habitat?Do they have different heritable traits?Are there differences in their DNA?3. Arrange all of the cards in a line along a continuum:Definitely theDefinitelydifferent speciesSomewhere betweensame species

Question

What evidence led to these decisions? There should be at least one line per pair. Salmon & GoldfishGrizzly Bears & Polar BearsSince salmon and goldfish are both fish, they have manyGrizzly bears live in diverse habitats in the norther hemi-traits in common. But they have many differences too.They live in different habitats, they eat different food, theysphere, where they eat a wide array of fruit, plants, andmeat. Polar bears live in frozen lands to the north, wherebehave differently, they have very different anatomy-andthey roam on ice sheets and hunt seals. The two bearsthey never interbreed. A large body of evidence showshave different anatomy and behavior, and they are broadlyconsidered to be different species. DNA analysis estimatesthat they diverged from a common ancestor about 400,000years ago. Yet once in awhile, at the edges of their ranges,they do meet and interbreed. Using genetic testing, re-searchers have identified multiple &#34;grolar bear&#34; hybrids inthat they descended from a common ancestor, yet at somepoint in the distant past, maybe their ancestors weren't sodifferent from one another.the wild.Fly Agaric MushroomsCommon & AustralianBlacktip SharksThese poisonous mushrooms live in many places around theworld. Different populations have different characteristics.Most are red with white spots, but others are yellow, orange,white, tan, or brown. Fly agaric mushrooms reproduceusing spores, which can travel by wind across greatThe common blacktip shark lives in coastal waters aroundthe world. The Australian blacktip shark, which lives offthe coast of northern and eastern Australia, looks almostidentical to the common blacktip-though it is smaller, itdistances. Because they are isolated, with little chance ofinterbreeding, populations living on different continentshave traditionally been considered different species. YetDNA analysis has shown that even populations living inlives in warmer water, it has a different number of ver-tebrae, and it has unique genetic markers. The two typesof sharks were once thought to reproduce only with theirown kind. However, using genetic markers, scientists haveNorth America form genetically distinct groups. Eachfound dozens of sharks off the coast of Australia that aregroup occupies a distinct habitat, and alleles do not mixfreely between them.hybrids between common and Australian blacktips. Same or Different Species?The Species ContinuumBackgroundFor organisms that reproduce with a partner, scientists generally define a species as a group ofinterbreeding individuals that don't breed with other groups. Using this definition, it's sometimes veryclear when two organisms are separate species.Yet we also know that, through natural selection, populations change over time. How much does apopulation have to change before we can call it a new species?Part of the trickiness in defining a species comes from the fact that species do not often form in aninstant. Usually, speciation is a process that happens gradually over long periods of time-typicallythousands or even millions of years. What we can observe is just a snapshot of this process in time.Instructions1. Get a set of Organism cards.2. Read the information on each card, and decide whether you think the organisms described arethe same or different species, or somewhere in between. Look for key information, such as:Do they interbreed?Do they live in the same habitat?Do they have different heritable traits?Are there differences in their DNA?3. Arrange all of the cards in a line along a continuum:Definitely theDefinitelydifferent speciesSomewhere betweensame species

Accepted Answer

The term "species" refers to a group of individuals who are genetically similar and can reproduce…