Building a Toy Version of Evo: A Step-by-Step Guide

In this blog post, I'll walk you through how I built a simplified version of [Evo](https://arcinstitute.org/news/blog/evo), focusing on its DNA sequence generation capabilities. This guide will help you understand the process and create your own version.

Understanding the Original Evo is a biological foundation model capable of DNA, RNA, and protein sequence generation and analysis. For our toy version, we focused on one core feature: DNA sequence generation with visual representation.

Project Setup We built this as part of the playground.vasa.bio collection, using Next.js 13 with TypeScript. Here's how we set it up:

1. Created a new page in the Next.js app directory: ```typescript // src/app/toy_evo/page.tsx 'use client';

import { useState } from 'react'; import { Button } from '@/components/ui/button'; ```

Core Components

### DNA Generation The DNA generation logic is straightforward: ```typescript const generateRandomDNA = (length: number = 20): string => { const bases = ['A', 'T', 'C', 'G']; return Array.from({ length }, () => bases[Math.floor(Math.random() * bases.length)] ).join(''); }; ```

### Visual Representation We created a DNAViewer component that color-codes each base: ```typescript const DNAViewer = ({ sequence }: { sequence: string }) => { return ( <div className="font-mono text-lg break-all"> {sequence.split('').map((base, index) => { const baseColors: Record<string, string> = { 'A': 'text-green-500', 'T': 'text-red-500', 'C': 'text-blue-500', 'G': 'text-yellow-500' }; return ( <span key={index} className={baseColors[base]}> {base} </span> ); })} </div> ); }; ```

### Main Component The main component ties everything together: ```typescript export default function ToyEvo() { const [dnaSequence, setDnaSequence] = useState<string>('');

const handleGenerateClick = () => { setDnaSequence(generateRandomDNA()); };

return ( <div className="min-h-screen bg-background p-8"> <div className="max-w-2xl mx-auto space-y-8"> <h1 className="text-4xl font-bold text-foreground"> Evo Toy - DNA Generator </h1> <div className="space-y-4"> <Button onClick={handleGenerateClick} className="w-full sm:w-auto" > Generate DNA Sequence </Button> {dnaSequence && ( <div className="p-4 rounded-lg border bg-card"> <DNAViewer sequence={dnaSequence} /> </div> )} </div> </div> </div> ); } ```

Styling We used Tailwind CSS for styling, following these principles: - Responsive design with `max-w-2xl` and `space-y-8` for layout - Color-coded bases using Tailwind's color classes - Consistent spacing with `p-8` and `space-y-4` - Proper typography with `text-4xl` and `font-mono`

Integration with Next.js 1. Used the app directory structure (`src/app/toy_evo/page.tsx`) 2. Added 'use client' directive for client-side interactivity 3. Leveraged existing UI components from the project 4. Followed TypeScript best practices

Testing To test the application: 1. Run `yarn install` to install dependencies 2. Start the development server with `yarn dev` 3. Navigate to `/toy_evo` in your browser 4. Click "Generate DNA Sequence" to see it in action

Key Features - Random DNA sequence generation - Color-coded visualization (A=green, T=red, C=blue, G=yellow) - Responsive design - TypeScript type safety - Integration with existing UI components

Live Demo You can see the live version at [playground.vasa.bio/toy_evo](https://playground.vasa.bio/toy_evo).

Conclusion This toy version demonstrates the basic concepts behind Evo's DNA sequence generation while keeping the implementation simple and educational. The code is available on GitHub, and you can extend it further by adding features like: - Custom sequence length control - Different types of sequence generation patterns - Additional sequence analysis tools - Export functionality

Feel free to use this as a starting point for your own experiments with DNA sequence generation and visualization!