Eocene

Similar in many ways to Miocene, the Eocene locus has no effect except to modify the evorsus phenotype, requiring at least one Ev allele to have any affect whatsoever. Furthermore, it is inactive if there is an M allele at the Miocene locus, the latter locus having a stronger effect upon Ev expression. Some loci are limited by island.

When creating a custom horse (or using the custom previewer), the user is asked to select the specific genotype at the Eocene locus, rather than choosing a phenotype and having the game select an appropriate genotype.

## Alleles

There are two Eocene alleles, with a simple dominance hierarchy, though the alleles are irrelevant if the horse doesn't have at least one Ev allele at the evorsus locus and/or does not display the evorsus phenotype.

### Eo

The Eo allele is thought to be the active Eocene allele, exerting a modifying affect over the actions of the Ev appaloosa allele. Rather oddly, it causes the Ev and ev evorsus alleles to behave as co-dominants, rather than their usual dominant-recessive relationship. Eo is dominant with respect to eo and can be obtained using an Add A Gene: Eocene item. It is only found on Antiquus and Ternio.

### eo

The inactive eom allele has no affect on the evorsus phenotype. It is recessive with respect to Eo and obtained by using a Drop Gene item and selecting 'Eocene'. It is found on all Paradisus islands. When the Eocene locus is homozygous for eo, it is not displayed in the genetics section of horse's character page.

## Phenotypes

The full range of Eocene phenotypes is in part determined by the genotype at the evorsus locus, and so that is also included in the following descriptions to explain how each phenotype is arrived at.

### Phenacodus Evorsus (EvEv / EoEo, Eoeo)

The phenacodus evorsus phenotype consists of a pattern of highly conserved creamy off-white markings that give are instantly recognisable. A broad strip of this colour begins on the horse's lower lip and extends along its lower jaw, throat, the front of its neck, its chest and its belly, ending at the groin. Small patches cover each eye, and the entire body carries narrow, tapering stripes of various lengths that run parallel to the horse's topline. These follow the curve of the horse's body, going down the neck, along the neck and finally curving down the top of the hind legs. Some also branch off and start to travel down the shoulder. However, the stripes never extend far down the legs. The mane and tail are not affected. As it requires the activity of the Ev appaloosa allele, this phenotype is never seen on donkeys or mules.

### Hyracoterium Evorsus (Evev / EoEo, Eoeo)

The hyracoterium evorsus phenotype includes the same lip to groin stripe and eye patches seen in the phenacodus evorsus phenotype, but the stripes travelling down the body are different. They are broader but less random, forming clear tracks from neck to rump, and most noticeably, are dashed - a series of very short stripes with space between them. The stripes may not curve down the horse's shoulder.

### Evorsus (EvEv, Evev / eoeo)

The evorsus phenotype is much less extensive than either pehnotype involving the action of the Eo allele. It consists of a white stocking on each leg, breaking up into white stripes similar to the primitive markings seen on countershaded and some dun horses, but inverted in colour. A pale, faded mask covers much of the face, petering out on the cheek panels, and the ears are tipped in white. As it requires the activity of the Ev appaloosa allele, this phenotype is never seen on donkeys or mules.