Wallace's Law of Species Evolution

LAW 1 states that every species has come into existence coincident both in space and time with a preexisting closely allied species, suggesting that species arise from existing ones.

The cumulative distributions of range sizes are highly skewed, indicating that most species have very small ranges and few have very large ranges.

Species tend to have overlapping ranges and are often found in close proximity to their closely allied species, with most species having very small ranges.

Species with smaller ranges may be more vulnerable to extinction, as they are more susceptible to habitat destruction and other environmental threats.

LAW 2 suggests that most species have very small ranges, which can contribute to high species richness and diversity in certain areas.

Wallace's laws provide important insights into the distribution and diversity of species, which can inform conservation efforts and strategies to prevent extinction.

Fewer species are found in these regions.

By chance alone, given the observed distribution of geographical range sizes.

They are often geographically concentrated.

They are species with small geographical ranges.

Small-ranged species are geographically concentrated, but not merely mirrored, and are often found in similar places for different taxa.

They are found in similar places despite their different evolutionary origins.

The patterns show small-ranged species and suggest common processes generate these species, which are different from species as a whole.

Islands provide the isolation needed for species formation, as shown in Figure 10.4, where small-ranged species are found in these areas.

The limitation is that some mountains, such as those in western USA and Canada, do not generate unusual numbers of small-ranged species, despite their glacial history.

The Appalachian mountains generate concentrations of small-ranged salamander species, but not birds or mammals, and the mountains of western North America generate concentrations of small-ranged mammals but not birds.

The patterns of small-ranged species have important consequences for conservation efforts, as they highlight areas of high species richness and diversity that require targeted protection.

The patterns of small-ranged species suggest that geographic range is negatively correlated with species richness, as species with smaller ranges are often found in areas of high species richness.