Plant Genetics

Every seed carries a library. Pages written by ancestors who never knew they were authors.

— Eden

Genetics in Eden determines everything about a plant—how fast it grows, what conditions it prefers, how long it lives, what color its flowers are. These traits are inherited, mutate, and evolve over generations.

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How Genetics Work

Every plant carries a genome—a collection of genes that define its traits.

The Basics

• Gene: A single hereditary unit with two alleles (one from each parent)
• Allele: A version of a gene (like "tall" or "short")
• Genome: The complete set of genes
• Phenotype: The expressed traits you can observe

Diploid Inheritance

Plants in Eden are diploid—they have two copies of each gene:

• One from the "mother" (seed producer)
• One from the "father" (pollen donor)

How these two combine determines what trait is expressed.

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Inheritance Types

Different genes follow different inheritance patterns:

Dominant/Recessive

One allele dominates the other:

Mother	Father	Offspring Shows
Dominant	Dominant	Dominant
Dominant	Recessive	Dominant
Recessive	Recessive	Recessive

Example: Tall (T) is dominant over Short (t)

• TT = Tall
• Tt = Tall
• tt = Short

Co-Dominant

Both alleles are expressed equally:

Combination	Result
Red + Red	Red
Red + White	Red and White (both visible)
White + White	White

Incomplete Dominance

Alleles blend together:

Combination	Result
Red + Red	Red
Red + White	Pink (blend)
White + White	White

The flower doesn't choose its color. It inherits a conversation between its parents—sometimes an argument, sometimes an agreement, always a surprise.

— Eden

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Plant Traits

Plants inherit many traits that affect their survival:

Growth Traits

Trait	What It Affects	Range
Stem Height	How tall the plant grows	Short to Tall
Leaf Size	Area of leaves	Small to Large
Root Depth	How deep roots grow	Shallow to Deep
Growth Rate	Speed of development	Slow to Fast

Environmental Adaptation

Trait	What It Affects	Range
Water Preference	Preferred soil moisture	Dry-loving to Wet-loving
pH Preference	Preferred soil acidity	Acidic to Alkaline
Drought Resistance	Survival in low water	Low to High

Reproduction Traits

Trait	What It Affects	Range
Flower Color	Visual appearance	Various colors
Seed Size	Size of produced seeds	Small to Large
Pollen Production	Amount of pollen made	Low to High
Cross-Pollination	Tendency to cross-breed	Self to Cross

Life Traits

Trait	What It Affects	Range
Longevity	Maximum lifespan	Short-lived to Long-lived
Photosynthesis Efficiency	Energy from light	Low to High

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Trait Expression

How genes become visible traits:

Water Preference Example

The Water Preference gene has three common alleles:

• W (wet-loving): Prefers moisture level 0.8
• M (moderate): Prefers moisture level 0.5
• w (dry-loving): Prefers moisture level 0.2

A plant with WM would prefer moderately wet conditions (blended).

Growth Rate Example

Higher values mean faster growth:

• Fast alleles: Speed up development
• Slow alleles: Slower, but may be more resilient

A fast-growing plant reaches maturity sooner but may be more vulnerable to stress.

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Inheritance in Action

When two plants cross-pollinate:

Step 1: Parent Genomes

Parent A: [GrowthRate: Ff, DroughtResist: Dd, WaterPref: WM]
Parent B: [GrowthRate: fF, DroughtResist: DD, WaterPref: Mw]

Step 2: Random Selection

Each parent contributes one allele per gene:

• From A's GrowthRate (Ff): randomly picks F or f
• From B's GrowthRate (fF): randomly picks f or F

Step 3: Offspring Genome

Offspring: [GrowthRate: Ff, DroughtResist: Dd, WaterPref: MM]

This offspring:

• Has moderate growth rate
• Has some drought resistance
• Prefers moderate moisture

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Mutation

Occasionally, genes change during reproduction.

How Mutations Happen

• Small random chance each generation
• Can affect any gene
• Most mutations are neutral
• Some are beneficial, some harmful

Mutation Effects

Type	Example	Result
Beneficial	Better drought resistance	Improved survival
Neutral	Different flower shade	No survival impact
Harmful	Reduced photosynthesis	Decreased survival

The Role of Mutation

Mutations are how new traits appear:

• A mutation in one plant
• If beneficial, that plant thrives
• Offspring inherit the mutation
• Over generations, it spreads
• The population adapts

Most mutations are forgotten. A few are remembered. Evolution is the slow accumulation of accidents that worked.

— Eden

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Natural Selection

Over time, better-adapted plants outcompete others.

The Process

1. Variation: Plants have different genetic traits
2. Competition: Resources are limited
3. Survival: Better-adapted plants survive longer
4. Reproduction: Survivors have more offspring
5. Inheritance: Offspring carry successful traits
6. Shift: Population genetics change over time

What Gets Selected For

In different environments, different traits are favored:

Environment	Favored Traits
Dry areas	Drought resistance, deep roots, dry preference
Wet areas	Wet preference, flood tolerance
Acidic soil	Acid pH preference
Competitive areas	Fast growth, tall stems

Observing Selection

Over many generations, you can watch:

• Dry-area plants becoming more drought-resistant
• Shaded areas favoring efficient photosynthesis
• High-competition areas favoring fast growth

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Genetic Diversity

Diversity is strength for a population.

Why Diversity Matters

• Resilience: Different plants handle different stresses
• Adaptation: Variety provides options for change
• Survival: If conditions change, someone is ready

Threats to Diversity

Threat	Effect
Isolation	Small populations become similar
Bottlenecks	Disasters reduce variety
Self-pollination	No new genes introduced

Maintaining Diversity

• Cross-pollination between different plants
• Migration of seeds between areas
• Connection between populations

The meadow that looks the same is hiding ten thousand differences. When drought comes, those differences become the only thing that matters.

— Eden

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Watching Evolution

As a Witness, you can observe evolution in real-time:

What to Watch For

1. Initial variation: Note differences between plants
2. Environmental pressure: Observe what challenges plants face
3. Differential survival: See which plants thrive
4. Reproduction patterns: Watch which plants produce seeds
5. Offspring traits: Compare children to parents
6. Population shifts: Note changing trait distributions

Timescales

• Individual life: See trait expression
• One generation: See inheritance
• Many generations: See evolution

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Continue learning:

→ How Plants Grow
→ Pollination
→ Creature Overview