Out of Line

Zoe is a cross between a male Grant’s zebra and a female quarter horse. Cletus is her half-brother whose father is the same Grant’s zebra but whose mother is a mammoth donkey. As zebra hybrids, they are collectively called zebroids.

Zoe the zorse and Cletus the zonkey are stars of the Answers in Genesis zoos.

Zoe and Cletus are two of our most educational animals because they demonstrate the biblical concept of created kinds. Genesis 1 says that God created the animals according to their kinds 6,000 years ago. Research suggests that the created kind typically falls at the family level of taxonomy. Horses, donkeys, and zebras are all species within the same kind (the equine kind), so they are genetically related. God did not create horses, donkeys, and zebras in Eden. He created generic equines that contained lots of genetic potential that has filtered down into the recognizable species we see today. Because they share a common equine ancestor, equine species are related and capable of hybridization.

While they usually inspire awe, I have often heard visitors mutter unpleasant comments about Zoe and Cletus. Words like unnatural and abomination are common, as are accusations of our staff trying to “play God.” But their parents bred naturally; they were not “forced” pairings. Wild zebras are not often exposed to domestic horses and donkeys to offer the opportunity for hybridization. But when people keep horses, donkeys, and zebras together, they may choose to interbreed.

Hybrids present a conundrum for scientists because they violate the traditional idea that once new species evolve, they should not breed with other species.1 Secular science teaches that all life evolved from a spontaneously arising single-celled common ancestor over billions of years, often illustrated by a “tree of life.” The mysterious common ancestor is the root of the trunk, and as genetic variation increased through naturalistic processes over time, organisms split into independent branches that should eventually stop sharing genetic information.

However, we see species within different genera, families, and even orders that are still hybridizing, which is puzzling for evolutionists. Also, the study of evolutionary biology has been heavily influenced by Ernst Mayr’s 1942 book Systematics and the Origin of Species, which states that hybridization is a destructive force that slows down or reverses evolution.2 Mayr’s ideas may have prejudiced the scientific world against hybrids.

These negative views translate over into the conservation world, where some consider hybrids a threat to the “purity” of species. Similarly, within the zoo world, animal hybrids are usually considered taboo. To display a hybrid that is not from a rescue situation is heavily frowned upon, and zoos may risk violating their accreditation rules for doing so. But from a biblical perspective, these rule-breaking hybrids are fascinating evidence of God’s design in animal kinds.

What exactly is a species?

The term species refers to one of the most specific levels of taxonomical classification. But what exactly defines a species? No one seems to have a solid answer. There is little agreement even in the scientific community. In my research, I have found nearly three dozen different definitions of the word species. From a biblical perspective, no modern species is pure, since every animal species today descended from the animal kinds created during creation week. Mixing is expected in their genetics.

Traditionally, a species has been distinguished by reproductive isolation, but this factor is constantly disproved. Species are interbreeding and creating hybrids everywhere, both under human care and in the wild. Contrary to popular belief, many hybrids are fertile and can reproduce, contributing their traits to their local populations.3 Even mules, arguably the most recognizable hybrid, are sometimes capable of reproduction.

More and more hybrids are being discovered that can successfully reproduce. In some cases, the hybrids are more fit (more likely to reproduce and pass on their traits) than their supposedly pure parents, such as with hybrids between California tiger salamanders and barred salamanders. Further complicating matters, many so-called pure species have evidence of hybridization in their genome. Polar bears, jaguars, and even Darwin’s finches (which are actually tanagers) all have evidence of hybridization in their DNA.4

But the secular community often vehemently opposes hybridization, even hybridization among wild animals. Some consider it to be a significant threat to the protection of species. The International Union for the Conservation of Nature, the global authority on conservation, considers hybridization as much a threat to the survival of species as disease, habitat loss, and pollutants.5 The United States Endangered Species Act is strongly against the protection of hybrids for the same reason.6

Some scientists support management strategies such as the isolation, removal, sterilization, or culling of hybrids,7 even if the hybrids involved are offspring of threatened species. For example, despite being threatened, 39 healthy Galápagos tortoises were sterilized in 2010 by the Iniciativa Galápagos program because they were hybrids.8 Also, the only known hybrid between a white rhinoceros (near threatened) and a black rhinoceros (critically endangered), born at South Africa’s National Zoological Gardens Game Breeding Centre in 1988, was killed due to the zoo’s policy against hybrids and because she was thought to have no breeding value as a hybrid.9

Hybrids

Liger

A hybrid of a male lion and a female tiger

Killer Bee

A hybrid of European and East African lowland honeybees

Leopon

A hybrid of a male leopard and a female lion. They have spots like leopards and heads that look like lions.

Dzo

A male hybrid of a yak and a domestic cow. Females are called dzomos.

Mulard

A hybrid of a male domestic Muscovy duck and a female domestic duck, which are derived from mallard ducks (different genera: Cairina and Anas)

Wholphin

A hybrid of a false killer whale and a bottlenose dolphin (different genera: Pseudorca and Tursiops)

Cama:

A hybrid of a dromedary camel and a llama (different genera: Camelus and Lama)

Grolar bear

A hybrid of a male grizzly and female polar bear

Hybrid Hypocrisy

If scientists cannot exactly define a species, who are they to say which organisms deserve to live and reproduce because of their purity? This practice has more echoes of “playing God” than allowing species to interbreed and their offspring to survive.

The idea that hybrids are taboo or unnatural also comes into question when genetic studies reveal that animals previously considered to be pure species turn out to be very common hybrids. This was the case with Clymene dolphins, now known to just be hybrids between spinner and striped dolphins.10 In fact, cetaceans (whales, dolphins, and porpoises) have become notorious for hybridizing in the wild. A 2016 study revealed 18 unique pairings of cetacean species, most of which occurred in the wild and most of which occurred between species considered not to be closely related.11

Recently, genetic studies on critically endangered red wolves suggest they are hybrids of gray wolves and coyotes.12 These results caused a stir because United States legislation, namely the Endangered Species Act, does not recognize or protect hybrids. These results could mean that the red wolf may lose its protected status as well as the millions of dollars spent on its captive breeding and recovery programs.

According to Roland Kays, head of the Biodiversity Research Lab at the North Carolina Museum of Natural Sciences, “What we’re finding with today’s high-resolution genetic tools is that hybrids are everywhere. . . . To say it’s a hybrid, so it’s not worth protecting, just doesn’t work anymore."13

As conservationists argue for the preservation of species and as those species turn out to be hybrids, prioritization, funding, and conservation come into question. At what point does hybridization in a genome make an animal a worthless hybrid or a valuable species in their eyes?

From a molecules-to-man evolutionary worldview, the disdain of hybrids seems counterintuitive because the worldview relies on change to progress the evolution of life. Natural hybridization should be a part of those changes. However, some conservationists insist hybrids are a threat. Instead of allowing these animals' adaptive processes to proceed, these conservationists are essentially working to prevent species or subspecies from hybridizing in the wild today, resulting in the isolation, sterilization, or culling of animals deemed unsuitable.14 But focusing too strongly on protecting individual species or subspecies may actually drive animals to extinction faster.15

Many wild birds hybridize within their kinds, including landfowl, waterfowl, shorebirds, hummingbirds, birds-of-paradise, and more. Shown here is a Lady Amherst's and golden pheasant hybrid.

Hybrid Helpers

Some researchers are starting to realize that hybridization can save species and can have positive repercussions on the environment.16 Hybridization can lead to new, improved biodiversity and may enhance the adaptability of species to ever-changing environments, especially as humans continue to expand our influence further into habitats.17

For example, a group of scientists argue that to save the dwindling tiger population (there may be only around 4,000 tigers remaining worldwide), conservationists should stop hyper-focusing on preserving the nine subspecies of tigers exactly as they are and be open to allowing the many hybrid tigers to contribute to the limited gene pool.18 They argue the more important goal is to save tigers, not the supposed purity of the subspecies. Likewise, critically endangered Florida panthers (a subspecies of cougar) almost went extinct because their isolation from other cougar populations meant that the inbreeding of so few individuals led to high numbers of genetic defects in the offspring. Conservationists were forced to accept that hybridization with cougars from another population in Texas was necessary to add genetic diversity to save them. The survival rate of the hybrid kittens was three times higher than kittens considered to be pure.19

God has called humans to be good stewards of his creation (Genesis 1:26–28; Psalm 8:6–9). We, therefore, should afford all animals our respect and kindness and not actively damage their environments or populations. However, in his wisdom, God also gave his creation incredible genetic diversity to interbreed and adapt (Genesis 1:20–25; Psalm 104:24–28). Allowing animals to diversify is one way they thrive in this world, even as humans encroach on their ecosystems.

Taxonomy

Carl Linnaeus, the Father of Modern Taxonomy (the classification of living things), was a creationist who acknowledged the natural order God put into creation. His book Systema Naturae introduced modern taxonomy to the scientific world. From broad to specific, his proposed seven basic taxons (groups) are kingdom, phylum, class, order, family, genus, and species.

However, we must remember that this man-made classification system is just that—man-made. Organizing creatures certainly helps us study them better, and we can see similarities among organisms because they have a common Designer. But created kinds do not all fit neatly into one taxon. They may fall at the order, family, or genus level. Taxonomy is always changing, and the classification of many organisms is in a constant state of dispute.

In today’s world, taxonomy is also heavily affected by presumed relationships within molecules-to-man evolution. What evolutionists today call cousins may not be consistent with Scripture. For example, secular scientists currently claim that sirenians (dugongs and manatees) and hyraxes (small furry mammals also called rock rabbits) are related. But Scripture tells us swimming creatures like the sirenian kind and land animals like the hyrax kind were made on different days of creation.

While Christians can refer to Linnaeus’ model, we must remember that modern taxonomy does not clearly represent the created kinds described in the Bible. We must use discernment when referring to man-made systems to interpret the world around us.

Plant Hybrids

While often discouraging animal hybrids, scientists usually encourage plant hybrids because they are usually more adaptable and have a higher tolerance for environmental stress. Hybridization often results in more uniformity, faster maturity, better disease resistance, and higher yields.

So why are hybrid plants celebrated but animal hybrids rejected? I’ve not found an answer.

The ancestors of today’s plants were created by God on day three of creation week. Like animals, each plant kind’s ancestors started with vast genetic potential. They reproduce according to their kinds, so their hybridization is consistent with a biblical worldview.

Most of the common plants we eat today are actually hybrids such as apples, avocados, bananas, carrots, clementines, coffee, lemons, peanuts, spinach, strawberries, sweet corn, watermelons, and wheat.

Popular hybrid flowers like stargazer lilies, sunburst dahlias, tea roses, and more add bursts of color to gardens.

Following the Rules

Far more common than most people realize, hybrids occur naturally within all classes of vertebrates as well as within the arthropod phylum (including insects, arachnids, crustaceans, and more). From sturddlefish (American paddlefish/Russian sturgeon) to boacondas (Columbian boa/yellow anaconda), and from swooses (mute swan/domestic goose) to narlugas (narwhal/beluga), hybrid animals abound both in nature and under human care.

But hybrids only occur within the same created kind. Grizzly bears and polar bears hybridize to create grolar/pizzly bears, and gray wolves and coyotes hybridize to create coywolves/wolfotes, but brown bears will never hybridize with gray wolves to create a new kind of animal.

Hybrids certainly present a controversial topic to those with a secular worldview because they run contrary to the idea of the isolation of species. Since the term species is an entirely man-made concept, it should be no surprise that animals do not always follow our rules. But they do follow God’s rules.

Unlike the single common ancestor of the molecules-to-man evolutionary worldview, the Bible speaks of multiple common ancestors representing each created kind. Those ancestors had vast genetic potential, allowing their descendants to adapt to the earth’s variety of ever-changing habitats, especially after the global flood.

The Bible explains why we see so much evidence of hybridization in species’ genomes: They have been changing throughout history from their common ancestors. Animals have never been static; God designed them to change.

Animals may not adhere to our definition of species, but they certainly adhere to God’s definition of kinds. Hybrids like Zoe the zorse and Cletus the zonkey are not unnatural abominations, but fascinating wonders that glorify the artistry and majesty of an all-knowing Creator.