How to implement a JavaScript-based tool for genealogical research and family trees?

Implementing a JavaScript-based tool for Genealogical research and family trees may seem like a daunting task. However, by breaking it down into achievable components, you can bring your concept to fruition.

In order to create a web application for creating and displaying genealogical trees and research, you would need to follow the steps hinted below:

Step 1: Design your Data Structure:

You need to design your data structure in such a way that it properly represents and handles the necessary information in a family tree (name, birthdate, death date, relationships, etc.).

A node-based tree structure would likely be the best representation of a familial relationship. Each node would represent a person and each connection between nodes would represent a familial relationship.

Step 2: Setup Your HTML:

You will use HTML to create the structure of the webpage. At this point, you just want to setup a basic HTML structure.

Here's an example of what you may want to include:

```html

In this HTML, you have created a div with the id "family-tree". This is where you will append your family tree once you have rendered it with your JavaScript.

Step 3: Create Your JavaScript:

Now you will need to create your JavaScript file that will render your family tree.

At this point, the JavaScript file will be fairly bare. Here's what it might look like:

```javascript
function createPerson(name, parent) {
return { name: name, parent: parent, children: [] };
}

function addChild(parent, child) {
parent.children.push(child);
}

var root = createPerson('John', null);
var jane = createPerson('Jane', root);
addChild(root, jane);
```

This createPerson function initializes a new person object with the given name and parent.

The addChild function adds a new child to the parent's children array.

Step 4: Render Your Family Tree:

Now that you have created your data structure and added some people to your tree, you need to render it on your webpage.

Here's a simple function that could render your tree:

```javascript
function renderPerson(person, parentElement) {
var el = document.createElement('div');
el.textContent = person.name;
parentElement.appendChild(el);

 person.children.forEach(function(child) {
   renderPerson(child, el);
 });

}

renderPerson(root, document.getElementById('family-tree'));
```

This function creates a new div for each person, sets the text of that div to the person's name, and appends the div to the parent element. Then it recursively renders all children of the person.

Step 5: Expand Your Tools:

From here, you will need to decide what additional tools and features you want to add to your genealogy web application. You might want to include tools for adding new people to your family tree, for searching your family tree, or for exporting your family tree to a different format.

Step 6: Add CSS Styles:

To make your family tree more visually appealing and user friendly, you can add CSS styles. You can do so by linking a CSS file in your HTML and/or adding inline styles in your JavaScript.

Here's an example of inline styling:

```javascript
el.style.border = '1px solid black';
el.style.padding = '5px';
el.style.margin = '5px';
```

Please note that due to the complexity of the topic, a full-fledged code cannot be provided here. Also, depending upon the exact requirement, various libraries and tools such as The D3 JavaScript library, Sigma js, Vis js etc. could be included to achieve the desired functionality.